I think I read somewhere to put a radio under the house with loud music on. I think the idea is to let it play all night when they are trying to sleep. I don't know if it works but I always thought it was a funny solution because....how are the people supposed to sleep through loud rock and roll under the house? What we have done if get the big traps from the animal control officer and put a can of cat food or sardines in the trap BUT first get the glad super sized garbage bag that you can fit the whole trap in. Leave the trap door at the open end of the bag and this way you can check the trap in the morning without getting sprayed. If it's the neighbours cat in there, you can let it out and try again.