The Screamer

We have a screamer in our alley, and when it gets going, the noise rings throughout the back half of the condo.

The screamer is a squirrel. It usually hangs out on the utility pole right outside the back room, which is Jeff's office/fort. It perches on the wires and screeches to beat the band. Sometimes it paces up and down the pole, screaming all the while. Yesterday when we went to the basement to get the tree box, it was hiking up and down the railing of our next door neighbor's back deck, stopping every few steps to, well, scream. We have tried to figure out what it is screaming at, but it does not appear to have a target of its wrath.

We don't know if it is simply royally pissed off at the world in general, or if it is simply mental.

Is there such a thing as a screwball squirrel in real life?