I have squirrels in my attic. It drives me nuts. Unfortunately, I'm replacing my roof and soffits in about a month in a half. I say unfortunately because of the $$$$$. On the plus side, it should eliminate any access points. Until then, I found these things online which I am going to put in various spots. I just got them so I don't know if they work. According to reviews, which I take with a grain of salt, they work pretty well in attics and gardens. I'm sure a bigger challenge to make them work on trees.