Did the squirrel emit a loud "cheer cheer whoosh whoosh" sound? I have had a squirrel yell at me too while it was waving it's tail wildly and that is what it sounded like to me. :)
Yes! It was waving it's tail too! Actually, my father and I decided that it might have been trying to distract us from two other squirrels nearby. Two others were running away from us while that one kept screaming to keep our attention.
