The term "a pellet gun" is much too broad. As others have pointed out they range in power quite a bit. Some will certainly NOT kill a squirrel but if you search the internet you'll find a video of someone killing a buffalo with a "pellet rifle".
Growing up I had an model 1894 Daisy that was used to teach squirrels, stray dogs, and wandering tom cats that our yard, feeders, dogs, and cats were best left alone. I never put a hole in a hide but could sting them if I could see them. Today I've got a gamo whisper and I'm quite certain that ANY animal I shot with it would have a penetrating wound.
Squirrels are game animals in most states. Shooting them or harassing them in any way might well be illegal so check first.
Growing up I had an model 1894 Daisy that was used to teach squirrels, stray dogs, and wandering tom cats that our yard, feeders, dogs, and cats were best left alone. I never put a hole in a hide but could sting them if I could see them. Today I've got a gamo whisper and I'm quite certain that ANY animal I shot with it would have a penetrating wound.
Squirrels are game animals in most states. Shooting them or harassing them in any way might well be illegal so check first.