Squirrels bark, scream and squeak. They're quite chatty animals and communicate with other animals vocally and with their tails. Sometimes their barks can be mistaken for bird calls, but their voices are distinguishable from birds by their tone and quality. Birds have sharp, clear, hollow-sounding chirps while squirrels' barks sound tighter, guttural, and forceful. When they're in distress, they make a sharp, urgent squeak that's a clear indication to their peers that there's danger nearby.