Hoverfly responses to looming stimuli depend on elevation and speed

An object on immediate collision course generates a rapidly expanding visual stimulus on the retina, which will typically trigger a fast reaction, such as an evasive behavior.

An object on immediate collision course generates a rapidly expanding visual stimulus on the retina, which will typically trigger a fast reaction, such as an evasive behavior. In hoverflies, for example, visual looming stimuli may be generated if the insect is about to collide…