What are bedbugs and what are their basic characteristics?

What are Bed Bugs?

Origins and History

The bedbug (Cimex lectularius) is a hematophagous insect whose evolutionary lineage traces back to the early Cretaceous period, as evidenced by fossilized specimens preserved in amber. Its earliest documented presence appears in ancient Egypt, where hieroglyphic depictions and burial records suggest a long‑standing association with human dwellings. Classical Greek and Roman texts also reference “cimicids,” indicating the pest’s prevalence throughout the Mediterranean basin.

During the Middle Ages, trade routes facilitated the spread of bedbugs across Europe and into Asia. The insects thrived in densely populated urban centers, exploiting the close proximity of humans and the limited hygiene standards of the era. By the 17th and 18th centuries, bedbugs had become a common nuisance in inns and households, prompting early pest‑control measures such as the use of insecticidal powders derived from botanical extracts.

The 20th century witnessed a decline in infestations due to the widespread adoption of synthetic insecticides (e.g., DDT). However, the latter half of the century saw a resurgence linked to:

Increased international travel and tourism
Urban housing density and economic instability
Development of resistance to pyrethroid‑based chemicals

Contemporary research indicates that genetic analyses of modern populations reveal multiple introductions from distinct geographic sources, confirming the species’ capacity for rapid global dispersal. Historical patterns underscore the bedbug’s adaptability and its persistent coexistence with human societies over millennia.

Classification

Kingdom

Bedbugs (Cimex lectularius) are members of the kingdom Animalia, a broad taxonomic group that includes all multicellular, eukaryotic organisms that obtain nutrients by consuming other organisms.

Key characteristics of the animal kingdom:

Multicellularity with differentiated tissues and organs
Absence of cell walls; cells surrounded by flexible plasma membranes
Heterotrophic metabolism, requiring organic material for energy
Development from a blastula stage during embryogenesis
Predominantly sexual reproduction, with diverse reproductive strategies

Bedbugs exhibit each of these traits. Their bodies consist of specialized tissues such as musculature for rapid movement and a digestive system for blood feeding. Lacking a cell wall allows the flexible exoskeleton to expand after engorgement. As obligate hematophages, they rely entirely on host blood, fulfilling the heterotrophic requirement of the kingdom. Their life cycle includes egg, nymph, and adult stages, reflecting the developmental patterns typical of animal organisms.

Phylum

Bedbugs belong to the phylum Arthropoda, a major group of invertebrates distinguished by several key anatomical and physiological features.

External chitinous exoskeleton that provides protection and prevents water loss.
Body divided into repeated segments, often organized into specialized regions.
Jointed appendages enabling precise movement and manipulation of the environment.
Growth through periodic molting (ecdysis) to accommodate increasing size.
Bilateral symmetry and a ventral nerve cord that coordinates sensory and motor functions.

These arthropod characteristics are evident in bedbugs: their hardened outer shell shields them during feeding, their bodies consist of head, thorax, and abdomen, and each segment bears jointed legs and sensory organs that facilitate locating hosts and navigating habitats. The arthropod framework underlies the insect’s resilience, mobility, and capacity to exploit human environments.

Class

Bedbugs belong to the class Insecta, a group distinguished by a chitinous exoskeleton, a body divided into head, thorax, and abdomen, and three pairs of jointed legs attached to the thorax. Insects possess one pair of antennae, compound eyes, and typically two pairs of wings, although many species, including bedbugs, have reduced or absent wings.

Within Insecta, bedbugs are placed in the order Hemiptera, suborder Heteroptera, and family Cimicidae. This taxonomic positioning reflects their adaptation to a hematophagous lifestyle and their morphological traits.

Key characteristics of the class Insecta that are evident in bedbugs:

Segmentation: distinct head, thorax, and abdomen.
Exoskeleton: rigid cuticle providing protection and structural support.
Leg arrangement: three pairs of legs attached to the thorax, enabling rapid locomotion.
Mouthparts: modified into a proboscis for piercing skin and sucking blood, a common feature among heteropteran insects.
Development: incomplete metamorphosis (hemimetabolous), producing nymphal stages that resemble miniature adults.

Order

Bedbugs belong to the family Cimicidae, which is placed within the order Hemiptera. Hemiptera, commonly called true bugs, comprises insects with piercing‑sucking mouthparts adapted for extracting fluids from plants or animals. The order is distinguished by several morphological and developmental traits.

Mouthparts form a rostrum or proboscis enclosed in a sheath.
Forewings (hemelytra) are partially hardened near the base and membranous at the tip.
Development proceeds through incomplete metamorphosis: egg → nymph (several instars) → adult.
Abdomen exhibits a segmented arrangement with ventral scent glands in many families.
Antennae consist of 4–5 segments, often bearing sensory setae.

Within Hemiptera, bedbugs fall under the suborder Heteroptera, characterized by a distinct division of the forewing and a scent‑producing gland system. Cimicidae members retain the general hemipteran mouthpart structure but have evolved a flattened body, nocturnal activity, and a preference for blood meals from warm‑blooded hosts. These specializations align with the broader order’s adaptation for fluid feeding while reflecting the family’s niche as obligate ectoparasites.

Family

Bedbugs belong to the family Cimicidae, a group of obligate hematophagous insects within the order Hemiptera. Members of Cimicidae share a dorsoventrally flattened body, an elongated oval shape, and a size range of 1–7 mm. Their mouthparts form a piercing‑sucking rostrum adapted for extracting blood from warm‑blooded hosts.

Key traits of the family include:

Three‑segmented antennae positioned near the eyes.
Reduced or absent wings; most species are wingless, facilitating movement through tight crevices.
Pronotum covering the thorax, often bearing fine bristles that aid in sensory detection.
Hemimetabolous development: eggs hatch into nymphs that undergo five molts before reaching adulthood, each stage requiring a blood meal.
Ability to survive prolonged periods without feeding, with some adults enduring months of starvation.

Cimicidae comprises several genera, the most notable being Cimex (the common bedbug), Leptocimex, and Oeciacus. While Cimex lectularius and Cimex hemipterus specialize in human hosts, other genera exploit avian or bat hosts, reflecting the family’s ecological versatility.

Geographically, Cimicidae species occupy temperate and tropical regions worldwide, often associated with human dwellings, hotels, and shelters where they exploit close contact with hosts. Their reproductive strategy includes traumatic insemination, wherein the male injects sperm through the female’s abdominal wall, a distinctive feature of the family.

Understanding the family’s morphology, life cycle, and host preferences clarifies why bedbugs persist as pests and informs control measures targeting their specific biological traits.

Genus

The bedbug genus belongs to the family Cimicidae and is primarily represented by the taxon Cimex. Members of this genus are obligate hematophagous insects that feed on the blood of warm‑blooded hosts, most commonly humans. Morphologically, Cimex species exhibit an elongated, dorsoventrally flattened body, typically measuring 4–7 mm in length, with a reddish‑brown coloration that deepens after feeding. Their mouthparts are adapted into a piercing‑sucking proboscis, enabling efficient penetration of the host’s skin.

Key taxonomic and biological features of the genus include:

Species diversity: The genus contains several described species, the most widespread being Cimex lectularius (the common bedbug) and Cimex hemipterus (the tropical bedbug). Additional species are confined to specific geographic regions or host preferences.
Reproductive strategy: Females lay single eggs in concealed crevices; each egg hatches into a nymph that undergoes five instars before reaching adulthood. Development is temperature‑dependent, with optimal growth at 22–28 °C.
Habitat specialization: Adults and nymphs reside in close proximity to sleeping areas, exploiting cracks, seams, and furnishings for shelter. Their nocturnal activity pattern reduces detection risk.
Geographic distribution: Cimex species have a cosmopolitan presence, thriving in temperate, subtropical, and tropical environments. Human migration and international travel have facilitated their spread across continents.

Understanding the genus framework clarifies the biological underpinnings of bedbug infestations and informs control measures that target their specific life cycle stages and ecological preferences.

Species

Bedbugs belong to the family Cimicidae within the order Hemiptera, a group of obligate hematophagous insects that feed on the blood of vertebrates.

The family includes several species, but only a few regularly infest human habitats. The most prevalent are:

Cimex lectularius – the common bedbug, found worldwide in temperate regions.
Cimex hemipterus – the tropical bedbug, predominant in subtropical and tropical climates.
Leptocimex boueti – a species associated with bats and occasionally encountered in human dwellings near bat roosts.
Oeciacus vicarius – the swallows’ nest bug, specialized on avian hosts but capable of temporary human contact.
Haematosiphon inodorus – the poultry bug, primarily a parasite of domestic fowl, sometimes reported in poultry‑housing structures.

All Cimicidae share a flattened, oval body measuring 4–7 mm in length, a reddish‑brown coloration, and a pronounced proboscis for piercing skin. Species differ in subtle morphological traits such as the shape of the pronotum, the pattern of abdominal tergite markings, and the length of the antennae.

Geographic ranges correspond to host availability: C. lectularius thrives in temperate zones across Europe, North America, and parts of Asia; C. hemipterus dominates in Africa, Southeast Asia, and the Caribbean; the remaining species occupy niche ecosystems linked to specific wildlife or domestic animals.

Phylogenetic studies indicate that the genus Cimex diverged from other cimicids during the Cretaceous, adapting to human‑associated environments after the advent of permanent settlements. This evolutionary history explains the current predominance of C. lectularius and C. hemipterus in modern residences.

Basic Characteristics

Physical Appearance

Size and Shape

Bedbugs (Cimex lectularius) possess a characteristic morphology that distinguishes them from other household insects. Adult individuals measure approximately 4–5 mm in length, comparable to the size of an apple seed, and weigh around 0.5 mg. Nymphs are progressively smaller, ranging from 1 mm in the first instar to nearly adult dimensions in later stages. The body exhibits a uniformly oval outline, with a width of about 2.5–3 mm, and is markedly flattened from top to bottom, facilitating movement within narrow crevices and fabric fibers. The dorsal surface is smooth and glossy, while the ventral side is slightly concave, allowing the insect to cling tightly to host skin. Distinctive features include:

Antennae: Four-segmented, slender, extending forward from the head.
Mouthparts: Elongated, pierce‑sucking proboscis adapted for blood feeding.
Legs: Six short, spiny legs positioned laterally, each ending in a claw for gripping surfaces.

These dimensions and shapes enable bedbugs to remain undetected in bedding, furniture, and clothing, contributing to their reputation as effective human parasites.

Coloration

Bedbugs (Cimex lectularius) display a distinct coloration that aids identification and reflects physiological adaptations. The adult insect’s exoskeleton is generally a flat, oval shape measuring 4–5 mm in length, with a reddish‑brown hue that deepens after feeding due to the ingestion of blood. Nymphs appear lighter, ranging from pale yellow to translucent, and acquire the characteristic brown shade as they molt through five developmental stages.

Key aspects of bedbug coloration:

Reddish‑brown adult color – indicates mature, fed individuals; the pigment derives from hemoglobin breakdown.
Lighter nymphal tones – signal unfed or recently molted stages; color intensifies with each molt.
Glossy cuticle surface – creates a subtle sheen that can vary with humidity and temperature.
Color change after feeding – abdomen expands and darkens, providing a visual cue of recent blood meals.

Color variation serves as a practical diagnostic feature for pest‑control professionals, allowing rapid differentiation between live specimens, recently fed adults, and immature stages during inspections.

Body Segments

Bedbugs are tiny, wingless insects that feed on blood and belong to the family Cimicidae within the order Hemiptera. Their anatomy conforms to the typical hemipteran plan, divided into three distinct body segments that each serve specialized functions.

The first segment, the head, houses the piercing‑sucking mouthparts known as a rostrum, a pair of compound eyes, and antennae composed of four segments. The thorax follows, consisting of three fused sections—prothorax, mesothorax, and metathorax—each bearing a pair of legs equipped with claws and, in the mesothorax and metathorax, a pair of short, non‑functional wings (tegmina). The final segment, the abdomen, contains the digestive tract, reproductive organs, and a series of dorsal plates (tergites) that protect internal structures.

Head: rostrum, compound eyes, four‑segmented antennae, sensory setae.
Thorax: three sub‑segments, six legs, vestigial wings on meso‑ and metathorax.
Abdomen: elongated, flexible, houses gut, ovaries or testes, ventral plates (sternites).

The segmentation enables precise coordination of feeding, movement, and reproduction. The rostrum penetrates skin to draw blood, while the legs provide stability on fabric and furniture surfaces. Abdominal expansion accommodates blood meals, and the reproductive system resides entirely within this segment, allowing rapid population growth under favorable conditions.

Antennae and Legs

Bedbugs (Cimex species) are small, hematophagous insects that infest human dwellings. Their bodies are flattened dorsoventrally, facilitating movement within narrow crevices. The following points describe the morphology and function of their antennae and legs.

Antennae consist of four segments (scape, pedicel, and two flagellomeres).
Each flagellomere bears numerous sensilla, including mechanoreceptors and chemoreceptors that detect host heat, carbon‑dioxide, and vibrations.
The sensory setae are arranged in a dense, ventrally directed field, enhancing detection of approaching hosts.
Antennal muscles allow limited articulation, enabling the insect to sweep the sensory field while concealed.

The six legs are adapted for rapid crawling and clinging to fabric fibers and wall surfaces.

Each leg contains coxa, trochanter, femur, tibia, and tarsus, ending in a pair of curved claws.
The tibial spur provides leverage for anchoring on rough substrates.
Tarsal pads are covered with adhesive setae that generate friction against smooth surfaces.
Leg joints are equipped with proprioceptive organs that coordinate precise movements during nocturnal foraging.
Leg length and segment proportions vary between nymphal and adult stages, reflecting changes in mobility and host‑seeking behavior.

Life Cycle

Eggs

Bedbug reproduction centers on the deposition of tiny, oval eggs that measure approximately 0.5 mm in length. The eggs possess a smooth, translucent shell that hardens shortly after being laid, rendering them resistant to physical disturbance.

A female bedbug can produce 1–5 eggs per day, accumulating up to 200–300 eggs over her lifespan. Egg laying occurs in concealed locations such as mattress seams, furniture crevices, baseboard joints, and behind wallpaper. This behavior protects the eggs from environmental fluctuations and facilitates proximity to a future blood meal.

Key parameters of bedbug eggs:

Incubation period: 6–10 days at typical indoor temperatures (22–26 °C). Cooler conditions extend development, while higher temperatures accelerate hatching.
Hatching success: Approximately 80 % under optimal conditions; reduced humidity or frequent disturbances lower viability.
Detection: Eggs appear as small, white specks; they may be clustered in groups of 5–10 or scattered singly. Visual inspection with a magnifying lens improves accuracy.

Understanding the egg stage is essential for effective control measures. Interrupting the incubation cycle—through heat treatment, desiccation, or targeted insecticide application—prevents the emergence of nymphs and curtails infestation growth.

Nymphs

Bedbug nymphs represent the immature stages that follow egg hatching and precede adult development. Each nymph undergoes five successive molts, designated first through fifth instar, and each molt increases body size and wing‑pad development while retaining the species’ characteristic flattened, reddish‑brown body shape.

First instar: Approximately 1 mm long; translucent with a faint reddish hue; feeds on blood for 3–5 days before the first molt.
Second instar: Grows to about 2 mm; coloration deepens; requires a blood meal of 4–6 days before molting.
Third instar: Reaches 3 mm; cuticle becomes more sclerotized; feeding interval extends to 5–7 days.
Fourth instar: Measures around 4 mm; abdomen shows distinct segmentation; blood meals last 6–9 days.
Fifth instar: Approaches adult size at 5 mm; wing pads become visible; final blood meal lasts 7–10 days before the transition to adulthood.

Nymphal development depends on temperature, host availability, and blood‑meal quality. Optimal temperatures (approximately 25 °C) accelerate molting cycles, while lower temperatures prolong each instar. Unlike adults, nymphs lack fully developed reproductive organs and cannot lay eggs, but they possess the same piercing‑sucking mouthparts and exhibit nocturnal feeding behavior. Successful progression through the nymphal stages is essential for population growth, as each surviving nymph contributes to the emergence of a reproductive adult.

Adults

Adult bedbugs are the final developmental stage of the species Cimex lectularius. They measure 4–5 mm in length, display a flattened, oval body, and possess a deep reddish‑brown hue that lightens after feeding. Their exoskeleton is hardened, allowing movement across fabrics and cracks without damage to surrounding surfaces.

Feeding occurs exclusively on warm‑blooded hosts. Adults locate a host by detecting carbon dioxide and body heat, then insert a elongated proboscis to pierce the skin and draw blood. A single meal provides enough nutrients for several days of activity; however, the insect can survive several months without feeding under favorable conditions.

Reproductive capacity is a defining trait. After a blood meal, a female releases one to two eggs daily for up to five weeks, embedding them in crevices near the host’s sleeping area. Eggs hatch within 6–10 days, and the resulting nymphs undergo five molts before reaching adulthood. Adult lifespan ranges from four to six months, extending up to a year in cooler environments.

Key physiological features include:

Six legs adapted for rapid crawling on vertical surfaces.
Two antennae equipped with sensory receptors for chemical and thermal cues.
A pair of spiracles on each side of the abdomen for respiration.
A sturdy thorax housing the musculature required for swift, nocturnal movement.

Understanding these adult characteristics is essential for identifying infestations and implementing effective control measures.

Habitat and Behavior

Preferred Environments

Bedbugs thrive in environments that provide concealment, access to a blood meal, and stable microclimatic conditions. Their selection of habitats reflects these requirements.

Human sleeping areas – mattress seams, box‑spring folds, headboards, and bed frames offer direct proximity to hosts and numerous narrow crevices for hiding.
Furniture – upholstered chairs, sofas, and cushions contain stitch lines and padding that retain heat and moisture, supporting development.
Wall voids and baseboards – cracks, electrical outlets, and gaps behind wallpaper create sheltered zones where insects can aggregate undisturbed.
Luggage and personal items – suitcases, backpacks, and clothing provide transport vectors and temporary shelters during travel.
Temperature and humidity – optimal development occurs at 21–26 °C (70–79 °F) with relative humidity of 60–80 %; environments maintaining these ranges accelerate life‑stage progression.

These settings enable bedbugs to avoid light, remain close to a blood source, and preserve the humidity needed for egg viability and molting.

Feeding Habits

Bedbugs are obligate blood feeders that rely exclusively on mammalian hosts for nutrition. Their feeding cycle follows a predictable pattern that determines infestation dynamics and control challenges.

Host detection – Bedbugs locate victims through a combination of carbon‑dioxide plumes, heat gradients, and kairomones emitted by skin. Sensors on the antennae and maxillary palps respond within seconds of exposure.
Feeding time – A single blood meal lasts 5–10 minutes. The insect inserts its elongated proboscis, injects anticoagulant saliva, and draws up to 0.03 ml of blood, sufficient for several days of metabolic activity.
Feeding frequency – After a meal, adults and late‑instar nymphs may survive 5–10 days without additional blood, whereas early‑instar nymphs require more frequent meals, typically every 2–4 days.
Digestion – Blood is stored in the midgut, where proteolytic enzymes break down hemoglobin. Digestion proceeds over 48–72 hours, after which excreted waste appears as dark fecal spots near resting sites.
Post‑feeding behavior – Following a meal, bedbugs retreat to concealed harborages—seams, cracks, or fabric folds—where they molt, mate, or lay eggs. This nocturnal activity reduces exposure to light and disturbances.

Understanding these feeding habits clarifies why bedbugs thrive in close proximity to sleeping humans and why control measures must target both the blood‑feeding periods and the protected harborages they occupy.

Nocturnal Activity

Bedbugs (Cimex lectularius) exhibit a distinct pattern of activity that aligns with the darkness of night. Their circadian rhythm drives them to emerge from daytime refuges after the host’s lights are extinguished, typically between 9 p.m. and 5 a.m. During this interval they locate a blood source, pierce the skin with a tapered proboscis, and ingest a rapid, painless meal that may last several minutes.

Key aspects of nighttime behavior include:

Host‑seeking: Movement toward carbon dioxide and body heat gradients intensifies after darkness begins.
Feeding sites: Preference for exposed skin areas such as the face, neck, and arms, where the host is less likely to detect the bite.
Post‑feeding retreat: After engorgement, the insect returns to a concealed harbor, often in mattress seams, wall cracks, or furniture joints, where it digests the blood and molts.
Temperature dependence: Activity peaks when ambient temperatures exceed 20 °C (68 °F), facilitating metabolism and locomotion.

The nocturnal schedule reduces exposure to human disturbance and predation, allowing bedbugs to complete their blood‑feeding cycle with minimal interruption. Their ability to resume activity within minutes after a brief awakening further enhances feeding efficiency throughout the night.

Reproduction

Bedbugs (Cimex lectularius) reproduce through a process known as traumatic insemination, in which the male pierces the female’s abdominal wall with a specialized intromittent organ to deposit sperm directly into her hemocoel. This method bypasses the conventional genital tract and results in rapid sperm transfer.

After insemination, sperm travel through the female’s circulatory system to the ovaries, where fertilization occurs. Females can store viable sperm for several months, enabling continuous egg production without repeated mating. Under favorable conditions—temperatures between 20 °C and 30 °C and adequate blood meals—a female lays 5 to 7 eggs daily, embedding them in concealed crevices near host resting sites. An average clutch contains 200 to 250 eggs, hatching within 6 to 10 days.

The developmental timeline proceeds as follows:

Egg stage: 6–10 days, depending on temperature and humidity.
Nymphal stages: Five instars, each requiring a blood meal; each molt spans approximately 4–7 days.
Adult stage: Reached after the fifth molt, roughly 30–45 days from egg deposition.

Females require a blood meal to initiate oviposition; each meal supports the production of a new batch of eggs. The combination of stored sperm, frequent blood feeding, and a short generation time allows bedbug populations to expand rapidly, especially in environments where hosts are readily available.

Distinguishing Features

Comparison with Other Pests

Bedbugs (Cimex lectularius) are small, oval, wingless insects that feed exclusively on warm‑blooded hosts. Adult size ranges from 4.5 to 7 mm, coloration varies from reddish‑brown after a blood meal to pale when unfed. They locate hosts by detecting carbon dioxide and body heat, pierce the skin with a needle‑like mouthpart, and ingest blood for several minutes before retreating to hide. Reproduction involves traumatic insemination; a single female can lay 200–500 eggs over her lifetime, each hatching in about a week. Eggs are deposited in cracks, seams, and fabric folds, where they remain protected from many chemical treatments. Bedbugs survive without feeding for several months, extending to a year under cool conditions.

When compared with other common indoor pests, several distinctions emerge:

Fleas: Measure 1–4 mm, possess jumping legs, and feed on mammals and birds. Their life cycle includes a larval stage that consumes organic debris, unlike the direct blood‑feeding of bedbugs. Fleas transmit pathogens such as Yersinia pestis; bedbugs are not proven disease vectors.
Cockroaches: Length 13–35 mm, omnivorous, capable of surviving weeks without food or water. Cockroaches reproduce rapidly, producing oothecae containing dozens of eggs, whereas bedbugs lay individual eggs. Cockroach infestations are typically associated with sanitation issues; bedbugs thrive in clean, well‑maintained environments.
Termites: Wood‑eating insects, colony sizes in the thousands, with caste differentiation. Termites cause structural damage through cellulose consumption, a behavior absent in bedbugs, which never ingest plant material.
Mites (e.g., dust mites): Microscopic (0.2–0.5 mm), feed on skin flakes rather than blood, and do not bite. Their allergenic impact stems from fecal particles, contrasting with the visible bite reactions caused by bedbugs.
Ants (e.g., odorous house ants): 2–5 mm, forage for sugary substances, establish foraging trails using pheromones. Ant colonies are social and can occupy extensive indoor spaces; bedbugs remain solitary hunters, aggregating only in sheltered harborages.

Control strategies reflect these biological differences. Bedbug management relies on thorough inspection of harborages, heat treatment exceeding 45 °C, and targeted insecticide applications to crevices. Flea control combines host treatment, environmental sprays, and regular vacuuming. Cockroach eradication emphasizes sanitation, baits, and gel insecticides. Termite mitigation uses bait systems or barrier treatments in foundations. Mite reduction focuses on humidity control and frequent laundering. Ant suppression employs bait stations and exclusion of entry points.

Understanding these contrasts enables practitioners to select appropriate detection methods and interventions, minimizing misidentification and optimizing resource allocation.

Signs of Infestation

Bedbugs are small, wing‑less insects that feed exclusively on blood, typically at night. Their presence can be identified by specific indicators that appear before an infestation becomes severe.

Visible evidence includes:

Small, rust‑colored spots on bedding, mattresses, or furniture, representing digested blood.
Tiny, oval, tan‑brown insects about 4–5 mm long, often seen in seams, folds, or crevices.
Molted exoskeletons, which appear as translucent shells near hiding places.

Additional clues involve:

Unexplained, itchy welts or red bumps in a linear pattern on the skin, resulting from bites.
A faint, sweet, musty odor emitted by large colonies.
Presence of fecal stains, dark specks resembling pepper, on sheets or walls.

These signs typically appear together; early detection relies on careful inspection of sleeping areas, upholstered furniture, and surrounding walls. Prompt identification allows effective control measures before the population expands.