Who do bed bugs bite and who do they not bite? - briefly
Bed bugs bite humans and other warm‑blooded animals—including birds, dogs, and rodents—while they generally ignore cold‑blooded species such as reptiles, amphibians, and insects. They preferentially feed on sleeping or immobile hosts.
Who do bed bugs bite and who do they not bite? - in detail
Bed bugs (Cimex lectularius and related species) are obligate hematophagous insects; they survive only by extracting blood from vertebrate hosts. Their feeding behavior is governed by three main factors: host availability, physiological suitability, and environmental cues such as carbon‑dioxide, heat and body odor.
Hosts that are regularly fed upon
- Humans – primary source in most domestic infestations; they provide the optimal combination of temperature, CO₂ output and skin chemicals.
- Domestic mammals – dogs, cats and, occasionally, rodents. These animals are accepted when they share the sleeping area with people, but the insects show a clear preference for human blood when both are present.
- Avian species – chickens, pigeons and other birds can serve as hosts, especially in structures where birds nest close to human quarters (e.g., lofts, barns). Bird blood sustains development, though it is less preferred than mammalian blood.
- Bats – wild or captive colonies provide a viable food source; bed bugs have been recovered from bat roosts, indicating adaptability to this niche.
Hosts that are seldom or never bitten
- Reptiles and amphibians – ectothermic physiology produces insufficient heat and CO₂ to trigger the insects’ host‑seeking response.
- Fish and other aquatic vertebrates – lack of air‑borne cues and an unsuitable environment preclude feeding.
- Insects and other arthropods – bed bugs lack the anatomical adaptations to pierce exoskeletons and cannot digest non‑vertebrate hemolymph.
- Individuals with severe skin conditions that mask chemical cues may experience reduced feeding, though this is an incidental effect rather than a true avoidance.
Factors influencing host selection
- Carbon‑dioxide emission – the strongest long‑range attractant; larger mammals emit higher levels, making them more detectable.
- Skin temperature – insects gravitate toward surfaces around 30–34 °C; humans typically maintain this range, whereas cold‑blooded animals do not.
- Chemical profile – specific fatty acids, lactic acid and other volatiles on the skin guide the bugs to bite sites. Variations among species can alter attractiveness but do not create absolute immunity.
- Host accessibility – bed bugs cannot climb smooth vertical surfaces without assistance; thus, they feed on hosts that rest on or near their harborages (mattresses, cracks, furniture).
In summary, bed bugs will bite any warm‑blooded vertebrate that emits sufficient CO₂, heat and skin chemicals, with humans being the most common and preferred source. They do not feed on cold‑blooded animals, fish, insects, or other organisms lacking the physiological signals required for host detection.