From Science:
They can't use Facebook, but bats still manage to keep in touch with their social network. Bat colonies, which are made up of a few dozen members, split and reform many times throughout the year as individuals go off to roost in small groups or hibernate alone during the winter. But researchers have found that female bats, like humans and elephants, form subgroups that stick together over long periods of time. In a study published today in the Proceedings of the Royal Society B, researchers marked bats from two colonies with data loggers and tracked their nesting behaviors over 5 years. They found that it's not just family members who stay together; a network analysis showed that these girls' clubs were made up of bats from many different lineages and age groups. (Male bats are always solitary.) The researchers propose that bat society probably benefits from cooperative behaviors such as grooming and communication, which are always more fun with your girlfriends.
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