What do house‑dwelling bedbugs look like? - briefly
Adult bedbugs are flat, oval, reddish‑brown insects about 4–5 mm long; after feeding they swell and turn brighter red. Nymphs look like smaller, paler versions of the adults and have no wings.
What do house‑dwelling bedbugs look like? - in detail
Indoor bedbugs are small, flat, oval insects measuring 4–5 mm when unfed and 6–7 mm after a blood meal. Their bodies are reddish‑brown, becoming darker after feeding. The dorsal surface shows a pale, creamy‑white margin along the edges of the abdomen, creating a subtle “crown” shape. Antennae are short, segmented into five parts, and positioned near the eyes. Each leg ends in a tiny claw, allowing the bug to cling to fabric and paper.
Key visual characteristics:
- Size: 0.15–0.20 in (unfed); expands up to 0.25 in when engorged.
- Shape: Dorsoventrally flattened, resembling a tiny apple seed.
- Color: Reddish‑brown to mahogany; lighter marginal band on the abdomen.
- Eyes: Two dark, bean‑shaped compound eyes on the head.
- Antennae: Five‑segmented, brown, barely visible without magnification.
- Wings: Absent; flight is impossible.
- Exoskeleton: Hardened, smooth, lacking visible hairs or scales.
Nymphal stages resemble adults but are lighter in color and smaller, lacking the distinct abdominal margin until the third instar. After feeding, the abdomen swells dramatically, taking on a balloon‑like appearance. The head, thorax, and abdomen remain clearly delineated, facilitating identification under a microscope or with a hand lens.