What does a domestic bed bug look like? - briefly
A domestic bed bug is a tiny, oval insect about 4–5 mm long, reddish‑brown in color, with a flat body when unfed and a swollen, elongated abdomen after a blood meal. Its head is concealed beneath the thorax, and it has short, stubby wings that are not used for flight.
What does a domestic bed bug look like? - in detail
The common household bed bug (Cimex lectularius) is a small, oval‑shaped insect lacking wings. Adults measure 4.5–5.5 mm in length, about the size of an apple seed, and are roughly 2.5 mm wide at the abdomen. The body is dorsoventrally flattened, which enables it to hide in tight crevices such as mattress seams, bed frames, and furniture joints.
Coloration varies with feeding status. Unfed individuals appear pale, matte brown; after a blood meal they become a brighter, reddish‑brown hue and their abdomen expands. Following digestion, the exoskeleton darkens to a deep mahogany, sometimes with a slight orange tint on the abdomen.
Key morphological features include:
- Six short, hair‑like antennae on the head, each bearing three segments.
- Two compound eyes positioned laterally on the head.
- Three segmented thorax bearing three pairs of legs, each leg ending in a small claw for gripping fabric.
- A short, pointed proboscis (rostrum) used to pierce skin and draw blood.
- No wings or halteres, confirming a purely crawling mode of locomotion.
Nymphal stages resemble adults but are smaller (1 mm in first instar to 4 mm in fifth instar) and remain uniformly light brown until their first blood meal. Each molt adds a new exoskeletal layer, increasing size and darkening coloration gradually.
The exoskeleton is smooth, lacking noticeable hairs or spines, which contributes to the insect’s ability to move silently across linens. The dorsal surface displays subtle, irregular dark spots that become more pronounced after feeding. The ventral side is lighter, with the abdomen appearing slightly swollen after ingesting blood.
Overall, the insect’s combination of small, flattened body, reddish‑brown coloration after feeding, and absence of wings distinguishes it from other household pests such as carpet beetles or moth larvae.