How do bed bugs choose a victim? - briefly
Bed bugs locate a host by sensing carbon dioxide, body heat, and specific skin odors, then confirm a suitable feeding site through tactile contact before biting.
How do bed bugs choose a victim? - in detail
Bed bugs locate a suitable host by integrating several sensory cues that indicate a warm‑blooded animal. The primary attractants are:
- Carbon dioxide released with each exhalation; concentrations rise sharply near a breathing organism and trigger an up‑wind movement.
- Heat emitted from body surfaces; infrared receptors in the insect’s antennae detect temperature gradients of 30–35 °C, guiding the bug toward the source.
- Skin volatiles such as aldehydes, fatty acids, and lactic acid; these chemicals are sensed by chemoreceptors and vary with individual physiology, diet, and hygiene.
- Movement and vibrations; subtle disturbances in the substrate are interpreted as potential prey activity, prompting a search response.
Upon detecting these signals, a bed bug initiates a “host‑seeking” phase. It climbs onto the mattress or surrounding fabric, then uses its antennae to sample the air for CO₂ spikes and thermal cues. When the combined intensity of cues exceeds a threshold, the insect descends onto the host’s skin, pierces with its stylet, and feeds.
The selection process differs between life stages. Nymphs, which lack fully developed sensory structures, rely more heavily on aggregation pheromones left by adult conspecifics to locate communal shelters. Adults, equipped with more sensitive detectors, can independently assess host availability and may prioritize hosts emitting stronger CO₂ or heat signatures.
Additional factors influencing choice include:
- Host size: larger bodies produce higher CO₂ output and greater heat, making them more attractive.
- Blood type: certain blood groups emit distinct odor profiles; research shows a preference for type O over others.
- Sleep patterns: prolonged immobility reduces the chance of detection, encouraging feeding on individuals who remain still for extended periods.
The decision culminates in a brief feeding event lasting 5–10 minutes, after which the bug retreats to a concealed harbor. Repeated exposure to the same host reinforces the selection through learned recognition of the host’s unique chemical signature.