A squirrel's brain is about the size of a walnut.

If a squirrel has taken up residence in your attic or crawl space, the only practical way to remove them is by trapping.

The squirrel's erratic path while crossing a street is an attempt to confuse the oncoming vehicle... thereby causing it to change direction. This is obviously the squirrels biggest, and often last mistake.

http://www.squirrels.org/facts.html