I have never used this method before, but I have heard that instant mashed potatoes can get rid of mice. The explanation ran something like this. When the mice encounter a bait tray of dry instant mashed tater flakes they gorge on them. As you might expect , this causes an extreme thirst in them. As long as there is no ready supply of water for them indoors they go outside for a drink. When the little pests get to a puddle outdoors they assuage the thirst and seal the doom in one fell swig as the mashed spuds swell and kill them by internal pressures. As I said , never had opportunity to test it , though it sounds like it might work.