Been awhile since the wife and I fired up and ran the layout. Suddenly there were several switches that wouldn't throw one way or other. Little investigating showed several fine Z stuff motor wires chewed (plastic must have something delicious). Meanwhile wife observed a gondola of Hersey Kisses were AWOL and some wrappers were found here and there on layout.
Bought out the mouse traps and day later a pair of culprits were dispatched to where ever rodents go.