Why do bedbugs bite only one person? - briefly
Bedbugs are attracted to chemical cues—carbon dioxide, body heat, and specific skin odors—so a person who emits stronger signals receives more bites. The insects do not exclusively target a single individual; the perceived selectivity reflects varying levels of these attractants.
Why do bedbugs bite only one person? - in detail
Bedbugs locate a host through heat, carbon‑dioxide, and skin odors. Once a bug makes contact, it injects saliva containing anesthetic and anticoagulant compounds, then feeds for several minutes. After a blood meal the insect’s gut becomes distended, triggering a physiological signal that suppresses further feeding for 3–5 days. This post‑meal inhibition, combined with the insect’s limited capacity to store blood, explains why an individual who has just been bitten is unlikely to receive additional bites immediately.
Several biological and behavioral factors influence host selection:
- Chemical cues: Certain individuals emit higher levels of lactic acid, ammonia, or specific fatty acids, making them more attractive.
- Blood type and immune response: Some blood types (e.g., type O) and weaker local immune reactions can result in easier feeding and less irritation, encouraging the bug to remain on that host.
- Skin microbiome: The composition of skin bacteria alters odor profiles; a favorable microbiome can draw more insects.
- Feeding history: After a successful meal, a bedbug’s appetite is temporarily satisfied, reducing the likelihood of switching to another person until digestion is complete.
Environmental conditions also play a role. In heavily infested settings, multiple bugs may cluster around the same host simply because that host provides a reliable, readily available source of blood. Conversely, in low‑level infestations, a single insect may concentrate its activity on the most chemically attractive individual.
In summary, the combination of post‑meal satiety, host‑specific chemical attractants, and the insect’s limited storage capacity results in a pattern where a bedbug often concentrates its bites on one person before moving on to another.