Hi James, squirrels are especially tough since they can jump. squirrel baffles can be put around the tree trunks but if there are any nearby trees or buildings they will just jump from those. There are hot pepper sprays that can be used but depending on how many squirrels are present it may not work well. some people have found frightening devices such as CDs on strings to help in some areas. Have you tried discussing this with your neighbor to let the animals fend for themselves in summer? I wish I had better answers but it usually requires multiple items for any success. good luck