How mosquitoes find their human targets
Mosquitoes seem particularly good at finding humans to bite, and now scientists have a better idea why.
According to a new study, the insects have a multi-sensory strategy that involves odors, visual cues, and body heat which is used to draw them closer to their prey.
It is believed that from about 10m to 50m away, they can smell exhaled carbon dioxide, or CO2; about 5m to 15m away, they can see the target; then, within 1m, body heat gets detected.
To test the way their senses work, researchers released mosquitoes into the controlled setting of a wind tunnel which had one visual cue, a black dot in the floor.
They found that when CO2 was injected into the air, the insects became interested in the spot on the ground; otherwise, with just background air, they were not attracted to it.
One of the researchers explains, “They only pay attention to visual features after they detect an odor that indicates the presence of a host nearby.”
A separate test was conducted that indicated a preference for heat regardless of CO2 levels in the air.