. . are not so much of a problem. They may not know "right" from "wrong" (our concept of it anyway) but they have a very keen sense of what they can get away with.

I met the smartest cat in the world in my pigeon coop, many years ago. It was before the condos were built. I was working in the back yard and a guy over the back fence asked, "Do you know there's a cat in your pigeon coop?"

I thanked him for the notice and went to investigate. Sure enough, there was a big orange cat in the rafters, and all the pigeons were on the other side of the coop watching the cat with intense interest.

I walked up to the cat, who was just above eye level. He sized up the situation, rolled off the rafter into my arms and started to purr.

I mean, what can you do with a cat like that except put him out and tell him not to try that again.

How do I know he was the smartest cat in the world? Because I never saw him again. He correctly calculated that this trick would work exactly once, and that next time pain would be involved.

Cats are very responsive to being whacked with a stick. It's not the minor pain, it's the intense injury to their dignity that's just too much to bare. They'll do whatever it takes to avoid that happening again.

Possums, on the other hand are just too stupid to learn from anything, including a good whipping, but they aren't up to the extreme gymnastics necessary to get into the coop, nor do they have strength enough to pull wire away, so I haven't had possum problems for years now.