Dogs with canine compulsive disorder may chase their own tails; lick, chew or suck obsessively on their skin or fur; snap at nonexistent creatures in the air (a phenomenon known as «fly snapping»); spin around and around for long periods of time; feel compelled to chase lights, shadows or other visual phenomena; become fixated to playing with a particular toy; or bark constantly, even when there is
no obvious reason for alarm or excitement.