I agree it might be possums or raccoons. Try hot pepper sprinkled around they don't like the smell. Careful of the bobcats. We have to be real careful with our cats that go outside, we have bobcats and coyotes who love cat snacks. Some of our cats are more than snacks in size, but we watch them when they are outside and make them stay on our property. We can't control the raccoons or the possums... the possum smell is pretty gross.