Predator proofing the coop is necessary, but if my neighbor and I weren't trapping and shooting, we'd be knee deep in the darned things. The land owner here scatters cat food all over, there's all kinds of neat stuff to eat, plus this place is excellent habitat for well, everything. The possums want to live in the land owner's house with him and I've had them run across my feet while sitting in there talking with him, and the skunks too - they just smell up the place. I had a large possum try to set up housekeeping in the space under my sink (my trailer no longer has the physical integrity it had about 50 years ago when it was new) and would not quit, so he got trapped and put down. No we can't get 'em all, but it does make a difference to keep the numbers down.