Hairs on the toes of Mexican free-tailed bats fluoresce under UV light, a new study reports. The function of the toe glow is unknown.

Mexican free-tailed bats belong to a family called Molossidae, and all the bats in this family have what scientists call “spoon-shaped bristles” on their outer toes.

Not all bats seize their prey on the wing. Some specialize in catching land insects like grasshoppers or roaches that are found on the ground, rocks, or trees. In this instance, less energy is ...