What does an old bed bug look like? - briefly
An aged bed bug measures about 5–7 mm, shows a darker, reddish‑brown coloration, and has a flattened, elongated body. After a blood meal its abdomen swells and turns a vivid red, making it noticeably larger than unfed individuals.
What does an old bed bug look like? - in detail
An aged bed bug presents several distinctive physical traits that differentiate it from younger stages and freshly fed individuals.
The body measures approximately 5–7 mm in length, slightly larger than a newly molted nymph. The exoskeleton becomes more heavily sclerotized, giving the surface a glossy, brown‑to‑dark brown hue. The dorsal surface often shows a mottled pattern of lighter and darker patches, a result of accumulated wear and repeated blood meals.
The abdomen is noticeably expanded after multiple feedings, appearing rounded and distended. When fully engorged, the abdomen can swell to nearly twice the normal thickness, giving the bug a “sausage‑shaped” silhouette. In contrast, an unfed older specimen retains a slimmer, elongated profile.
The head is proportionally smaller relative to the body, with a pair of beaded eyes set on the lateral margins. Antennae remain slender, composed of five segments, each segment bearing fine sensory hairs. Legs are six‑jointed, ending in small claws that facilitate clinging to fabric and seams.
Color changes accompany age and feeding status:
- Unfed, mature bug: uniform reddish‑brown to dark brown.
- Partially fed: abdomen shows a reddish‑orange tint, while the thorax remains darker.
- Fully engorged: abdomen turns bright red or orange, with the thorax retaining its darker shade.
The wings are vestigial, reduced to tiny, non‑functional pads, confirming that the insect is flightless throughout its lifespan.
Overall, an elderly bed bug is characterized by a larger, more robust body, hardened dark exoskeleton, variable abdominal coloration reflecting feeding history, and the same basic anatomical features—head, antennae, legs, and vestigial wings—as younger adults.