Dealing with our own mouse infestation these last couple of weeks. Eliminating them only seems to have annoyed the colony and we're seeing droppings in places we hadn't before.
The kill count is up to 17, with one captured alive and freed miles away (on my way to work). We want to be nice - but the little turds aren't wandering into the humane traps like we had hoped, nor are they climbing into bowls of shallow oil to get trapped. Hell, somehow they're managing to eat the bait sometimes and not trip a kill trap. My best bet is the sill of the basement. I haven't caught a single one on the basement floor, or on the 1st floor. No signs of them on the 2nd floor. So my best guess is that they're climbing the walls inside to get around, and scooting up the gaps around heating pipes under the heat registers to pass between floors.
What prompted this crusade was discovering a mouse nest inside my wife's car... inside the engine compartment. It was a "Hey, what's that burning smell?" discovery. So we trapped a couple outside, under her car, and I put a trap inside the basement to check for signs there. Only after we killed the first dozen did we start seeing shit on counters and floors upstairs. I'm guessing they know something's reducing their numbers and they're looking for a new nesting ground.
We're using the Tomcat plastic jaw traps. They're pretty sensitive, and the bait cup is big enough to jam a piece of dog kibble into tightly.
