What do bedbugs look like and how big are they? - briefly
Bed bugs are flat, oval insects with a reddish‑brown hue and no wings. Adult specimens measure roughly 4–5 mm (about 0.2 inches) in length.
What do bedbugs look like and how big are they? - in detail
Bedbugs are small, oval‑shaped insects with a flat dorsal surface that becomes more convex after feeding. Their exoskeleton is smooth, lacking wings or noticeable hairs, and the coloration ranges from light brown in unfed individuals to a deeper, reddish‑brown after a blood meal. The head is concealed beneath the pronotum, giving the appearance of a single, rounded body segment. Six legs emerge from the thorax, each ending in tiny claws adapted for clinging to fabric. Antennae are short, filamentous, and typically not visible without magnification.
Size varies with developmental stage and recent feeding:
- First‑instar nymph: 1.5 mm long, pale in color.
- Second‑instar nymph: 2.0 mm long, slightly darker.
- Third‑instar nymph: 2.5 mm long, brownish.
- Fourth‑instar nymph: 3.2 mm long, more pronounced reddish hue after feeding.
- Adult: 4.5–5.5 mm in length, 2.5–3 mm wide, dark reddish‑brown when engorged, lighter brown when empty.
Eggs are about 0.5 mm long, white, and deposited in clusters on seams or crevices. The adult’s abdomen expands up to 2.5 times its unfed size after a blood meal, temporarily increasing overall dimensions but returning to the baseline after digestion. These measurements place bedbugs among the larger members of the Cimicidae family, distinguishable from similar pests such as carpet beetles or cockroach nymphs by their flattened, oval profile and lack of hard wing covers.