What Is The Real Reason Behind An Animal Chasing Their Tail?

Tweet

During the course of my life, I have owned a number of cats, dogs, birds, and fish as pets. Throughout this "ownership" period many of the cats and dogs, and one parakeet I had would often chase their tails, going in circles for hours sometimes catching it, sometimes not. Now for the most part I know or can assume this is a form of play for them, but just recently I was given a kitten and the only time he acknowledges that he has a tail is either when one of my adult cats scares him or if he is trying to eat and he happens to move his tail in such a manner it comes into view, he will sit and growl at it and when it don't move he will than proceed in chasing it. So it has gotten me to wonder again what's the purpose of tail chasing. I know we may never know the real reason behind it, but I think it would be fun to read what others may come up with.