Sprinkle a bunch of cayenne pepper onto the peanut butter, Arif. The squirrels hate it!!
Have fun with your girls, glad I was able to contribute to your Sunday fun. Maybe you can share pictures of your results.
(Not pictures of the fleeing squirrels, but pictures of your peanut butter/seed/pepper clad apples!)
It is a really good project for children, thanks for sharing it with yours.