Humans aren't the only species who like to hang out with their own social networks. It turns out that bats also have their own groups of friends that they prefer spending time with.

A new study by scientists from the UK's Center for Ecology and Hydrology, the University of Exeter and the University of Oxford found that bats have distinct social groups they stick with, even though they change their roosts every few days.

Researchers studied bats for five years in a wooded area called Wytham Woods in the UK. They fitted over 1,500 bats with small aluminum armband tracking devices that showed where the bats roosted when they moved to new roosts.

Each bat social group had its own space within the woods and none of those spaces overlapped, although both species occupied the same area of forest. This suggests that the bat social groups are defensive of their territories. When bats moved, changing their roosting areas, their groups moved with them. Researchers also discovered that some of the social relationships of the groups were long-term, with most lasting at least several years.

"Learning about bats' social structure helps us understand how best to protect populations in the wild, but this study is only the beginning, we still have a lot to learn," says Dr. Tom August from the Center for Ecology and Hydrology.

Researchers studied two species of bats. One called Natterer's bat forms social groups with mixed sexes. However, the other group, Daubenton's bat, has social groups defined by gender, groups are either all male or all female.

Researchers found this grouping "fascinating," especially considering that the way animals socially organize is still not really understood.

"Just as some types of people are super-connected on Facebook, this work shows that in animal systems, two very closely related species living in the same habitat can have very different kinds of social network," says Dr. Fiona Matthews from the University of Exeter.

Unfortunately, bats in the U.S. and Canada suffer from dwindling populations. A fungus called White-nose syndrome has devastated many species of bats, including more than 95 percent of brown bats in New Jersey. The fungus attacks when bats hibernate, taking advantage of their lower body temperatures and decrease in energy.

Bats are generally misunderstood by those who fear them. These flying creatures actually help us by eating many of the insects that destroy crops and farmland.

Photo Credit: U.S. Geological Survey