A few years ago a feral tom cat appeared near the hangar. I began putting out water and dry food for it and every morning the food was gone.
After months the cat would come into the hangar. Months after that I was able to touch it. Old cat with one ear missing.

The cat has for the last two years lived full time in the hangar. He sleeps on a folded up quilt way up on a cabinet shelf under a 100-watt bulb that is left on full time in cold weather. He comes and goes as he wishes through a 'doggy door' I put in the wall.

The past few days all his wet and dry food is completely gone. He never eats that much, so obviously something else is getting into the hangar and eating the food. Could be a coyote, a skunk, or another cat. I can't figure out whch.

Some sort of motion detector that could somehow turn on my small video camera would solve the mystery, but I don't have the equipment on hand for that.

How would you solve what animal is involved here?