How do bedbugs find a person at night? - briefly
Bedbugs locate a sleeping host by sensing the heat and carbon‑dioxide plume emitted by the body, using specialized thermoreceptors and chemoreceptors that guide them along the gradient. Their peak activity occurs during nighttime hours, coinciding with human sleep, which maximizes the chance of contact.
How do bedbugs find a person at night? - in detail
Bedbugs locate a sleeping host by integrating several sensory cues that operate in darkness.
Temperature gradients guide them toward the warm body heat emitted by a human. Their thermoreceptors detect minute changes, allowing movement up the thermal plume that rises from the skin.
Carbon‑dioxide exhaled during respiration creates a localized concentration cloud. Chemoreceptors on the antennae sense this gas, directing the insect toward its source.
Odor molecules released from the skin and sweat, such as fatty acids and lactic acid, act as kairomones. These chemicals are detected by olfactory sensilla and reinforce the path indicated by heat and CO₂.
Vibrations caused by breathing, heartbeat, and limb movements generate substrate‑borne signals. Mechanoreceptors on the legs respond to these low‑frequency oscillations, helping the bug fine‑tune its approach.
In the absence of light, visual cues are irrelevant; the insect relies entirely on the above modalities. The combined effect produces a chemotactic and thermotactic gradient that the bedbug follows until it reaches the host’s surface, where it can feed.
Key sensory mechanisms