Have you seen the bird without wings?

Every now and again you will hear something that you can't get out of your mind. Like a song you can't get out of your head. Where I live squirrels live freely in our yards. You get use to them chasing each other constantly running from tree to tree. Then I heard someone refer to them as Tree Rats. They said unlike the rats that go inside your home they are free to roam in anyone's yard they choose. I don't see them as tree rats but more like a bird without wings.