How does a hungry bedbug look compared to a full one?

How does a hungry bedbug look compared to a full one? - briefly

A «hungry» bedbug has a slender, collapsed abdomen and less pronounced body curvature, whereas a «full» specimen displays a swollen, rounded abdomen and a smoother, fuller outline.

How does a hungry bedbug look compared to a full one? - in detail

A bedbug that has not fed appears markedly smaller than one that has recently taken a blood meal. The abdomen of a starved specimen is narrow, almost cylindrical, and the overall body length ranges from 4 mm to 5 mm. The exoskeleton is lighter in color, often a pale brown or tan, because the cuticle contains little internal material.

In contrast, a recently engorged insect displays a dramatically expanded abdomen that can reach 7 mm to 9 mm in length. The abdomen becomes rounded and balloon‑like, pushing the head and thorax upward. The cuticle darkens to a deep reddish‑brown hue as the blood fills the digestive tract. The legs may appear more splayed due to the increased body volume.

Key visual distinctions:

  • Size: narrow (≈4 mm) vs. expanded (≈8 mm).
  • Shape: cylindrical vs. rounded, bulging abdomen.
  • Color: pale tan vs. dark reddish‑brown.
  • Leg posture: compact vs. slightly spread to accommodate swelling.

These characteristics allow quick identification of feeding status in field observations.