About a hundred years ago, when I lived in the middle of some 20 acres of oak trees, we had a "bird feeder" about 10 feet outside our kitchen windows. It was simply a flat, round, probably 18" diameter disk on top of a piece of 3/4" pipe which the other end was driven into the ground, and overall about 4 feet tall, with some long, 1/4" bolts penetrating the disk, protruding upward with the top ends ground to a point. We would get chunks of suet from the butcher, and impale them on these spikes. Birds loved this in the wintertime, especially once the ground was well covered in snow. One morning, we found a full grown possum sitting up there having a feast. He was still there that evening. And still the next morning. Still eating from time to time, but mostly just chilling. We finally decided that maybe he could not figure out how to get back down.
In case you've never noticed, those rascals have some serious, needle-like teeth, and, when you are up close, seemingly quite a few of them! He did not appreciate it when we walked outside for a closer look, and showed ALL of those teeth! I went back inside, got my welding gloves, and went back out...to the same greeting. I gently just batted him off the disk into the deep, soft, snow, where he "played possum" for actually about an hour, before getting up and waddling away.