We have a problem. We have a cat door to allow our cat to go in and out. Lately a strange cat has come in and eats our cat's food. Question: how can we stop this? We don't want to lock the door at nite and we don't want to ignore the problem.
The foreign cat comes in after the house is quiet and only at nite. It comes in quietly and bolts quickly on any noise. We haven't seen it yet, only heard it jumping over the fence.
Our latest attempt is to get a alarm switch, one that gives a chiming noise when someone or something walks in front of it. This may work, but we will have to keep setting the switch every nite and the cat may get used to the noise. Our cat hardly pays any attention to it.