And this particular meece is smart; he won't touch the d-con pellets.
Also, he was able to eat the peanut butter on the mouse trap, without
tripping the trap. Two consecutive nights. Is this a Super Meece?
What to do, what to do??

First, decided which is more of a problem: the mouse or the spouse.

If the mouse let the spouse in, get a cat (Bengal tigers are nice).
Spouse traps are heavy and the bait tends to be expensive (but
diamonds work well). Be sure you don't get trapped yourself.

There are plenty of ways for a mouse to get in that doesn't require
them to be "let" in (I've seen them get in under closed garage
doors, up the garage door and into the attic, and from there it's
not hard for them to get into the house near furnace and A/C ducts.

Gordon L. Burditt