How do bedbugs bite? - briefly
Bedbugs penetrate the epidermis with a slender proboscis, release saliva that prevents clotting, and then draw blood. The resulting puncture sites appear as tiny, red, itchy welts, frequently arranged in a linear or clustered pattern.
How do bedbugs bite? - in detail
Bedbugs locate a host by sensing body heat, carbon dioxide, and movement. Once a suitable spot is identified, the insect climbs onto the skin and inserts its elongated, straw‑like mouthparts, known as a proboscis, into the epidermis. The proboscis consists of two interlocking stylets: one pierces the skin while the other delivers saliva.
The saliva contains anticoagulants, vasodilators, and anesthetic compounds. These substances prevent blood clotting, widen capillaries, and temporarily numb the bite area, allowing the bug to feed undisturbed. Feeding typically lasts five to ten minutes, during which the insect withdraws up to 0.01 ml of blood.
After engorgement, the insect withdraws the proboscis, releases excess saliva, and retreats to its hiding place. The bite site may remain unnoticed for several hours; inflammation and itching often appear later as the immune system reacts to the foreign proteins.
Key points of the feeding cycle:
- Detection of host cues (heat, CO₂, motion)
- Ascension onto skin and proboscis insertion
- Saliva injection with anticoagulant and anesthetic agents
- Blood extraction lasting several minutes
- Withdrawal and return to shelter
Repeated bites can lead to clustered, erythematous welts, sometimes arranged in a linear or zigzag pattern reflecting the insect’s movement across the skin. The severity of the reaction varies with individual sensitivity and the amount of saliva introduced.