Squirrels are cute little rodents that frequent our yards and parks. They generally don't bother anyone unless they're fed:

If you feed them, they learn to beg, and then to demand.

Even if you manage to get them very tame, they will bite if startled. When I share peanuts with my blue jays, the squirrels come too. Once the peanut stops bouncing across the ground, the squirrels frequently can't see it. They appear to find it by smell. They can jump from the roof to a branch or a wire, so they have good enough vision; I don't know how to explain the way they sniff around for a peanut they watched land inches away and sometimes still can't find it.