Wen

Killing squirrels will do nothing, they'll just make more. Do a search for animal repellants and you will find a few ultrasonic products. I HIGHLY suggest them. These work incredibly well, and we are on ground level with an abundance of wild things. Mine is motion activated.

I attribute some of my luck to this (the local hawks help too). Mine is positioned in a place where my most important trees are, so on a balcony it should do wonders for you.

And mothballs are fantastic too, I agree. Great for sheds or garages.

I've never had a problem with our many squirrels, bunnies, deer, rats, chimpmunks, or cats. Ducks on the other hand either don't hear it or don't care.