How do small bed bugs bite? - briefly
Small bed bugs use a needle‑like proboscis to puncture the skin and inject saliva that contains anticoagulants, causing a painless puncture followed by a red, itchy wel‑whelm. The bite often appears as a small, clustered spot that may develop a raised bump after a few hours.
How do small bed bugs bite? - in detail
Small bed bugs 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, needle‑like proboscis, which consists of a stylet bundle capable of penetrating the epidermis without breaking the surface. The tip of the stylet delivers a minute quantity of saliva that contains anesthetic compounds, preventing the bite from being felt, and anticoagulant agents that keep blood flowing.
The feeding process proceeds as follows:
- Stylet insertion: the mouthparts pierce the outer skin layer, reaching capillaries.
- Saliva injection: enzymes and anticoagulants are released to inhibit clotting and numb the area.
- Blood uptake: the bug draws blood through the hollow canal of the proboscis, using a slow, rhythmic pumping action.
- Detachment: after 5–10 minutes, the insect withdraws its mouthparts and drops from the host.
During feeding, the bug’s saliva can provoke a localized immune response, resulting in a raised, red welt that may itch. The size of the bite correlates with the amount of saliva introduced rather than the insect’s body size. Repeated feeding on the same site can cause larger lesions due to cumulative irritation. The entire cycle, from host detection to disengagement, occurs without the bug leaving a visible mark on the skin, which explains why bites are often discovered only after swelling appears.