Why don't bedbugs bite everyone at night? - briefly
Bedbugs feed only when a host emits sufficient cues such as heat, carbon‑dioxide, and specific skin chemicals; individuals who produce weaker signals or have stronger skin defenses are less likely to be targeted. Therefore, not every person in an infested environment receives a bite.
Why don't bedbugs bite everyone at night? - in detail
Bedbugs locate a host by detecting carbon‑dioxide, heat, and skin volatiles. Individuals who emit lower levels of these cues attract fewer insects. For example, a person with a slower metabolic rate releases less CO₂, reducing the signal that triggers the parasites’ approach.
Skin characteristics influence feeding success. Thick epidermis, calloused areas, or dense hair can impede the insect’s ability to pierce the surface. Additionally, temperature gradients on the body affect probe placement; cooler skin regions are less appealing because they indicate reduced blood flow.
Chemical composition of sweat varies among people. Certain fatty acids, lactic acid, and ammonia act as attractants, while other compounds such as deodorant residues or specific pheromonal blends can repel. The microbiome on the skin metabolises sweat into volatile substances; a diverse bacterial community often produces a broader spectrum of attractants, increasing bite probability.
Host immune response also matters. Some individuals develop rapid inflammatory reactions that cause itching and swelling within minutes. The resulting discomfort may prompt the bedbug to disengage before completing a blood meal, leading to fewer observable bites.
Behavioral patterns modify exposure. Frequent movement during sleep, sleeping on a hard surface, or using tightly woven mattress covers limit the insect’s access to exposed skin. Conversely, prolonged periods of stillness on soft bedding create an optimal environment for the parasite to locate a feeding site.
Bedbugs exhibit selective feeding behavior. After a successful blood meal, an engorged insect can survive several days without feeding, decreasing the need to bite additional hosts. In a mixed‑host environment, the parasite often concentrates on the most attractive individual, leaving others untouched.
Key determinants of bite distribution:
- Metabolic CO₂ output
- Body temperature and peripheral blood flow
- Skin thickness and hair density
- Sweat composition and associated volatile compounds
- Skin microbiome profile
- Speed and intensity of immune reaction
- Sleeping posture, movement, and protective barriers
Understanding these factors clarifies why night‑time feeding is not uniform across all occupants of an infested space.