A study at Tel Aviv University has found that Egyptian fruit bats make noises in their colonies to actually communicate with one another. Most bats make loud random noises when they congregate in their colonies. But until now, researchers hadn’t known whether their calls served a specific purpose or they were simply making random noises.

According to the paper published in the journal Scientific Reports, the researchers recorded bat sounds and movements on video, capturing 15,000 vocalizations to learn more about bats. And, using a voice-recognition system, they were able to connect certain sounds made by the bats to certain social situations and interactions like arguing over food, mating and sleeping clusters, and difference of opinion.

The team also found that the bats tended to change their tones when addressing members of the opposite gender. Much of the loud harsh or strident noise in a bat cluster is bats “voicing their annoyance with those in very close quarters around them,” the team suggests.