When male big brown bats (Eptesicus fuscus) send sonarlike signals known as echolocation into the air, they’re not just looking for food—they’re also telling other bats to back off. The find comes thanks to an analysis of audio recordings of the animals taken while they foraged for food in a lab. Some of the calls were different from the bats’ usual short echolocation pulses; they were lower in frequency, longer in duration, and always occurred in sets of three to four calls. To find out what purpose these strange calls served, the scientists made video and audio recordings of big brown bats as they hunted tethered mealworms. In some setups, the bats flew alone, and in others they hunted in pairs (as in the photo above). When flying alone, the bats did not utter the foraging call; it was only when a male was paired with another bat (male or female) that he emitted the sound—and then, it was only the males that did so. The male bat making the most foraging calls usually got the prey, while the other male moved farther away, the researchers report online today in Current Biology. Female bats never called “dibs,” perhaps because in the wild they are more likely to forage near relatives, the scientists say. Intriguingly, each male bat had his own foraging call—sounds that were so distinctive, the scientists were able to correctly identify the caller 96.4% of the time.