Insect

Butterflies taste with their feet. Chemoreceptors on their leg tips (the tarsi) detect sugars and chemicals the instant they land, about 200 times more sensitively than the human tongue. Females taste a plant with their feet before laying eggs, so their caterpillars can eat it.

Nymphs of the planthopper have actual gear-like teeth on their hind legs. When jumping with 400G in 2 milliseconds, the gears synchronize both legs within 30 microseconds. Adults lose the gears—damaged ones can't be replaced—and switch to friction instead.

When bees are repeatedly exposed to explosive scents followed by sugar water, they eventually extend their tongues at the smell alone. A real device was built with 36 trained bees in sensor cartridges as an explosive detector. Training a dog takes months, but bees need only a few hours.