The mothers at this time are ravenous, and must eat more than their body weight in insects each night since they are eating for two. Their fave foods include moths, beetles, dragonflies, flies, wasps and ants, so for homeowners hoping to control insects like flies and ants, bats are a huge help.
To human eyes, the baby bats look basically the same, but a mother bat can find her own pup among the millions -- primarily based on scent and sound -- when she returns after hunting. The atmosphere in the cave is intense, with all of the bat pups vocalizing at around the same time, hoping to grab their mother's attention.
RELATED: Why You Shouldn't Be Scared of Vampire Bats
The video shows the massive number of bat mothers leaving the cave, an exit that begins about three hours before sunset. The females must nurse their pups at least twice daily, so their evening hunts are limited by that need.
The pups learn to fly when they are 4–5 weeks old. Bat Conservation International reports: "If all goes well on its first flight, a young bat drops into complete darkness, flies at a speed of at least 20 feet per second, and turns an almost complete somersault with millimeter precision to land on the cave wall just seconds after taking off."