Foxes make a wide variety of calls depending on the situation and their species, including a rapid series of barks, a scream-like howl and a sharp alarm call that sounds like a sharp bark or cough. Foxes also "gekker," which is a term for a type of guttural chattering.
Researchers believe that the rapid barks practiced by red foxes is used as an identification system, since studies have shown that foxes can tell each other apart by their calls. Fox parents commonly use the alarm call to alert their children to danger. Adult foxes generally gekker at each other in aggressive encounters, and kits also gekker during play.