Bats all have one pup at a time, twins being a rare exception. All bat species are K-selected, meaning parent investment in their young is high. This means the juveniles are usually born more highly-developed, have higher survivorship, and are fewer in number. Humans are another example.

Each of those babies has its own mother, and each of the mothers knows exactly which baby is hers. They are incredibly spatially aware and good at remembering where they left their pup when they go out to hunt. They also recognize their pups through smell and sound.