Angry shore birds have been attacking drones flying over New York City’s beaches, the Associated Press reports. The 3-feet long drones, which emit a loud hum, are being used by cops and other city agencies to patrol for sharks and struggling swimmers, but in their mission to protect and serve they have aroused the ire of birds. Veronica Welsh, a wildlife coordinator at the Parks Department, said the birds were “very annoyed by the drones” from the moment they arrived on the beach. “They will fly at it, they’ll swoop at it, they’ll be vocalizing,” Welsh told the AP. “They think they’re defending their chicks from a predator.” City officials told the AP the “swarming incidents” have been primarily carried out by American oystercatchers, which lay their eggs this time of year in the sand on Rockaway Beach. David Bird, a professor of wildlife biology at McGill University, said the shore birds could eventually get used to the drones, but he aded that the presence of the drones could also make some birds flee the beach and abandon their eggs. He told the AP, “We do know there are birds on this beach that are highly endangered. If they abandon their nests because of the drones, that would be a disaster.”