What do fleas respond to? - briefly
Fleas are attracted to host‑generated cues such as body heat, carbon dioxide, movement, and specific skin odors. These stimuli direct them to locate and attach to an appropriate host.
What do fleas respond to? - in detail
Fleas are highly attuned to specific environmental cues that trigger feeding, movement, and reproduction. Their sensory apparatus detects:
- Carbon dioxide (CO₂) emitted by warm‑blooded hosts; concentration gradients guide fleas toward a potential blood source.
- Body heat sensed through thermoreceptors; temperature differentials of 30–37 °C indicate the proximity of a mammal or bird.
- Vibrations and air currents generated by host locomotion; mechanoreceptors in the antennae and legs translate these signals into directional movement.
- Chemical odors such as lactic acid, ammonia, and certain fatty acids present in skin secretions; olfactory receptors discriminate these compounds to locate suitable hosts.
- Light intensity influencing activity cycles; many flea species display negative phototaxis, seeking darkness for resting and laying eggs.
During the quest for a blood meal, fleas integrate these stimuli, prioritizing CO₂ and heat as primary attractants, while odorants refine host selection. After engorgement, the insect shifts focus to environmental conditions favorable for egg development: high humidity, moderate temperature, and the presence of organic debris. Egg hatching and larval growth are stimulated by fungal spores and bacterial metabolites, which provide necessary nutrition. Adult emergence is triggered by rising temperatures and decreased moisture, prompting the newly formed flea to seek a host using the same sensory cues described above.