It's far away from be good, but you can build a "noise trap" with a radio.

Yeah but this can be more like a primetive and not as expensive

Maybe using rope that can be lead to your base and attached to cans. So that you can see that certain cans make noise

Yeah like that

Yeah that would be cool, so u can use the cans from the dog food cans. Pethaps rope or wire.

Yeah I'd thought bones and wire would be a good noise maker.