The problem is that feral mice are crawling with bad stuff. Here in the NE, they are the prime repository of lyme disease, although the deer usually get the blame. If you look closely at those cuties, you may find they carry lice, mites, ticks and things that are much smaller and far more deadly.

I fully agree on using peanut butter and spring traps, but won't use poisons where other animals may be affected.