The outdoor portion of our Central Air unit is a mouse hotel

[NewJeffCT]

it seems. Found out last night when we came home to find the A/C not working. I replaced a fuse on the indoor unit and it fired up for a minute or two before stopping. Then, the service guy on the phone said it might be mice got into the A/C unit and chewed two copper wires there... sure enough, that was it - I saw at least 3 mice out there (one was small & brown, one grey and one big fat one that was also brown). I separated the wires and replaced the fuse again and it worked. One of the handiest things I've done in my life (very low bar on that one, though)

However, is there a way besides killer traps and/or poison to keep them out of there and prevent further wire chewing?