Why don’t bed bugs bite? - briefly
They bite only to obtain a blood meal needed for reproduction and will not feed unless they are hungry.
Why don’t bed bugs bite? - in detail
Bed bugs (Cimex lectularius) require a blood meal to progress through each developmental stage, yet they do not bite continuously. After a successful feeding, an individual remains engorged for several days to weeks, during which it digests the blood and produces eggs. During this post‑meal interval the insect’s mouthparts are inactive, so no further probing occurs.
Feeding is triggered by specific cues: body heat, carbon‑dioxide exhalation, and movement. When these signals are weak or absent—such as in a vacant room, during the day when the host is away, or in a heavily insulated environment—the insect does not initiate a bite.
Physiological factors also limit biting frequency. The digestive process requires enzymes to break down hemoglobin; until these enzymes are replenished, the bug cannot process another meal. Hormonal regulation, chiefly through juvenile hormone, controls the timing of the next feed, ensuring that the insect does not attempt multiple bites in rapid succession.
Environmental conditions influence activity. Temperatures below 15 °C (59 °F) slow metabolism, reducing host‑seeking behavior. Conversely, temperatures above 30 °C (86 °F) can increase movement but also raise desiccation risk, prompting the bug to conserve energy and delay feeding.
In summary, a bed bug’s bite is a regulated event dictated by:
- Recent blood intake (post‑meal quiescence)
- Presence of host cues (heat, CO₂, motion)
- Digestive enzyme availability and hormonal cycle
- Ambient temperature and humidity
These mechanisms ensure that the insect bites only when necessary for development and reproduction, explaining periods when it appears not to bite.