I have been away for a while, did Rooster get rid of this mouse yet?
If not, then here is an idea. Where I live, we have these things called Nutria. They are basically huge rats with big orange-colored teeth. Really friggin ugly. [
en.wikipedia.org]
These things like to crawl around in our drainage canals. They eat the grass and burrow in he dirt and really screw up the canals. A couple of years ago, they were very overpopulated and presented a real problem.
One of the local sheriffs down here decided to solve the problem by instructing his deputies to use the nutria for target practice. For a couple of weeks, you could see police walking the canals popping every nutria they saw.
My suggestion to Rooster is: shoot that rat and feed him to the geese! (to paraphrase one of my favorite songs.) Just don't poison it. I've had first hand experience with that! They sometimes will crawl up into a wall and die a slow death in there. After another day or so, the stench of rotted rat permeates the house and lingers on for days. A really nasty smell that nothing will cover up. The only solution to that would be to tear the wall open and remove the rotten rodent. Not a fun job.