What the heck do you think it could be?? We have a dog door but the other three would not let anything come in and run a muck without notice.
Mice is a thought but wouldn't we notice and how the heck could they eat that much food?? We are talking a bowl at least 10 inches around and 2-3 inches of food. I am freaked out! We confirmed last night that it was there at 11 pm and gone by 3 am.