All dogs and cats are to be on a leash outside here! In the beginning, I did just that..my cat in a harness with a leash. But now, since management can't see my apartment, I just leave my door open for him to do as he pleases. Everything scares him home anyways. The flies come in and the wind blows dirt in, but the benefit out weighs that stuff. Besides, my cat can fly. Once in a while he catches a fly and his hunt for them is entertaining.