We used to have a mouse that liked to hide in our toaster and eat the crumbs out of that crumb tray that toasters have... We never saw the mouse, only its poop. And yes, it was disgusting. Oh, and here's an even more fun story....I've found mouse poops in our silverware drawer. Never have I disinfected so many utensils....*shudder*..
This was during our 4-year catless period after our other 2 cats died.
Now that we have a cat again, mice don't hide in our toaster or drawers.
Best mouse repellent we've ever had. More effective than traps too.
For people allergic to cats, there are some dog breeds that will do the job. Most terriers will hunt mice, as they are bred for it.
(Muahaha!)