So we have these neighborhood cats that come up to our back door and look at us inside as if to say "we know you can't get to us." Ugh, they get me so angry. If I even bother to chase them away ( they do look for birds in the trees, and I love birds), they don't run till I unlatch the door, open it up and chase them. Brave kitties!!! We also have squirrels that come around and eat the buds on our rose bushes. I know that there are devices that send out some kind of noise waves or something, to chase unwanted garden pests. Do you know what they are called? I'd like to get one. Thanks in advance for your advice.