October has taken the stage. The leaves blush red, pumpkins smile from porches and classic films retell the Slavic folklore of the night: vampires! Vampires may not be real, but their origins are linked to bats—one of the ecosystem’s most fascinating and spooky mammals.

Bats are nocturnal mammals that evolved with powered flight independently from birds and insects. Throughout millions of years of vertebrate evolution (animals with backbones), bats have developed many adaptations including flight and specialized feeding habits such as consuming blood. October is the perfect time to explore how these traits help bats to thrive on Earth.   

Getting their wings

Flight—seen in insects, birds and bats—evolved from different origins. A vertebrate with feathers and hollow bones called Archaeopteryx, was an early ancestor of birds that could fly. Insects, on the other hand, do not have a backbone. Their wings extend from their thorax, or the midsection of their body. Fossils suggest bats’ unique physiology evolved from four-legged insect-eating mammals. Over time, bats developed larger wings with more surface area, stronger forelimb muscles and thinner bones. This combination of structures gave rise to the only mammals capable of true flight. Flight aerodynamics makes the wings of birds better at cruising flight, while at lower speeds bats outperform birds when it comes to hovering and maneuvering.

Appetite for blood

Bats share more than just flight with the vampires of folklore. Like vampires, some bats exhibit an appetite for blood. Residing in Central and South America, vampire bats feed on the blood of birds, livestock and other mammals. But instead of sucking blood, they lap it up with their specialized tongue—and need around two tablespoons a day to survive. Vampire bats produce a specialized anticoagulant called draculin in their saliva, which keeps blood flowing and anesthetizes their prey before they strike. Vampire bats evolved with kidneys and a strong immune system capable of handling their unique diet. Their physiology lets them enjoy their favorite nocturnal meals.

This Halloween, keep an eye out for Earth’s real-life vampires. They are always searching for their next midnight snack.