One of my cats will eat anything that is soft plastic. He will eat shopping bags, cellophane wrappers, anything. Fortunately, he hasn't had any issues. I've seen plastic in his poop, so when he eats it, at least it passes. Once I heard him gagging somewhat in the middle of the night. I got up and saw him with a couple inch strip of plastic hanging out of his mouth. He was happily munching it down. I grabbed it and started pulling it out of his mouth. It was 3-4 feet long. He had gotten into the trash and ate the cellophane wrapper from a large box.

I have gotten in the habit of making sure there is never any plastic around, but every once in a while he finds some.

How can I teach him not to eat plastic?