New research shows that bees can recognize flowers by the plants' tiny electric field that differs between species. The electric field bends the tiny hairs on a bee's body, firing neurons located at the base of the hair. From the journal Science:
Such fields—which form from the imbalance of charge between the ground and the atmosphere—are unique to each species, based on the plant's distance from the ground and shape. Flowers use them as an additional way to advertise themselves to pollinators…
Electric fields can only be sensed from a distance of 10 cm or so, so they're not very useful for large animals like ourselves. But for small insects, this distance represents several body lengths, a relatively long distance.
"How bees sense a flower's electric field" (Science)
"Mechanosensory hairs in bumblebees (Bombus terrestris) detect weak electric fields" (PNAS)
