Everyone living east of the Mississippi River in the US is familiar with squirrels. They are also extremely common on the west coast inland as far as the Rocky and Cascade Mountain ranges. Seemingly every stand of trees in those wide areas contains squirrels. If you own a dog, the chances are it knows about the squirrels in your neighborhood trees as well. The jumpy little creatures seem to like to taunt domesticated dogs from the safety of their tree perches. They even go so far as to throw nut shells down at the helplessly obsessed animals below. At the very least, the squirrels commonly chirp or bark at the dogs. It seems to be a game for the squirrels, at least until one is a bit too careless and gets caught.