When have bedbugs bitten? - briefly
Bedbugs typically bite during the night while a person is asleep, preferring exposed skin such as the face, neck, arms, and hands. Bites appear as small, red, itchy welts often in a line or cluster.
When have bedbugs bitten? - in detail
Bedbugs (Cimex lectularius) feed exclusively on warm‑blooded hosts. Their activity follows a predictable pattern tied to the host’s sleep cycle, ambient temperature, and the insect’s physiological state.
During a feeding episode, an adult or late‑instar nymph locates a host, climbs onto exposed skin, and inserts its elongated proboscis. The bite typically occurs within 5–10 minutes after contact, allowing the insect to ingest 0.1–0.2 ml of blood. Feeding usually takes place at night when people are stationary and less likely to detect movement. In temperate climates, bedbugs become active after sunset, with peak biting between 10 p.m. and 4 a.m.
Several factors influence the exact timing of a bite:
- Host immobility: Bedbugs are more likely to feed when the host is asleep or otherwise motionless. Rapid movement or frequent position changes reduce feeding success.
- Temperature: Ambient temperatures above 20 °C accelerate metabolic rates, shortening the interval between host contact and blood ingestion. In cooler environments, feeding may be delayed or interrupted.
- Starvation level: After a period of deprivation (typically 5–7 days for adults), bedbugs become more aggressive and may bite earlier in the night to replenish reserves.
- Life stage: Nymphs require a blood meal to molt. First‑instar nymphs often bite shortly after emergence, while later instars may wait longer, depending on previous feeding history.
The bite itself is painless because the insect injects a mixture of anesthetic and anticoagulant proteins. Visible reactions—red, itchy welts—appear several hours later as the host’s immune response develops. The latency of the skin reaction varies among individuals, ranging from 30 minutes to 24 hours.
In summary, bedbugs bite primarily during the host’s sleep period, with peak activity in the early morning hours. Feeding onset follows a brief contact interval, is modulated by temperature, host movement, and the insect’s hunger state, and produces delayed cutaneous symptoms due to the pharmacologically active saliva.