When I was in college, I had a temp job at some office off Braddock. I took smoke breaks (I smoked when I was young and dumb) out front. Right where I smoked, some guy with a window office had a sign that said
"Beware Attack Squirrel"
which I thought was really odd.
A few days into the job, I was smoking a cigarette outside in the same location. This squirrel was on a tree about 10 feet away staring at me. I was curiously staring back at the rodent. All of a sudden, the vile tree rat jumped off the tree and charged right at me. I was so surprised the thing was attacking me that I screamed like a little girl and ran for cover.
Anyway... squirrels do, surprisingly, attack on occasion.