What does a domestic bedbug look like and what are its dimensions?

What does a domestic bedbug look like and what are its dimensions? - briefly

A domestic bedbug is a flattened, oval insect with a reddish‑brown hue, six legs, and wing‑like pads. Adults are roughly 4–5 mm long (0.16–0.20 in) and about 2 mm wide.

What does a domestic bedbug look like and what are its dimensions? - in detail

The common household bed bug, Cimex lectularius, is a small, wing‑less insect with a flattened, oval body. Its dorsal surface is smooth and glossy, ranging from light brown after a recent blood meal to a darker, reddish‑brown hue when unfed. The abdomen tapers slightly toward the rear, and the head is concealed beneath the pronotum, giving the bug a seamless outline. Six short legs emerge from the thorax, each ending in a curved claw that aids in clinging to fabric. The mouthparts form a needle‑like proboscis capable of piercing skin to withdraw blood. Nymphs resemble adults but are lighter in color and lack the fully developed pigmentation of mature specimens.

Key size characteristics:

  • Length: 4.5–5.5 mm in adults; nymphal stages range from 1.5 mm (first instar) to 4 mm (fifth instar).
  • Width: approximately 2.5–3 mm at the widest point of the abdomen.
  • Weight: about 0.004–0.005 g for a fed adult; unfed individuals weigh slightly less.
  • Body shape: dorsoventrally flattened, facilitating movement between fabric fibers and mattress seams.

These measurements place the bed bug among the smallest hematophagous insects encountered in residential settings. The combination of a concealed head, elongated proboscis, and compact, flattened form distinguishes it from other household pests such as carpet beetles or fleas.