Why do bedbugs bite? - briefly
Bedbugs bite to acquire a blood meal essential for egg production and growth. Their saliva contains anticoagulants and anesthetic compounds that enable painless feeding.
Why do bedbugs bite? - in detail
Bedbugs require blood to develop and reproduce. Their mouthparts, called stylets, pierce the skin and inject saliva that contains anticoagulants and anesthetics. The anticoagulants keep the blood flowing, while the anesthetic reduces the host’s perception of the bite, allowing the insect to feed undisturbed.
Feeding occurs primarily at night when humans are asleep. The insect is attracted to carbon dioxide, body heat, and certain skin chemicals. Upon locating a host, it climbs onto exposed skin, usually the face, neck, arms, or hands, and inserts the stylet into a capillary. Blood is drawn for 5–10 minutes, after which the bug retreats to its hiding place.
The physiological need for blood stems from the production of eggs. A female must ingest several blood meals to mature an egg batch; each meal provides protein and lipids essential for oogenesis. In the absence of a blood source, development stalls and mortality rises.
Key factors influencing the biting behavior:
- Host detection: CO₂ emission, heat gradient, and kairomones.
- Feeding cycle: Nighttime activity, 5–10 minute feeding duration.
- Saliva composition: Anticoagulants (apyrase), vasodilators, anesthetic proteins.
- Reproductive demand: Multiple meals required for egg maturation.
Repeated exposure can lead to sensitization, causing stronger skin reactions such as itching, redness, or swelling. The reaction intensity varies with individual immune response and the quantity of saliva injected.
Understanding these mechanisms clarifies why the insect seeks blood, how it locates victims, and the biological purpose behind each bite.