With woods around we have one occasionally. It was worse maybe 30+ years ago when there were a couple of small snakes inside that had followed the mice. Major flashing and steel wool at the top of the foundation mostly worked but tiny gaps happen. Good luck.
Thanks Gwen. Unfortunately, this is not my first rodeo. You keep them out for a while and then they find a new way in. The good news is that I found a hole in the skirting that I’ve had somehow missed for years. Now I just have to find the hole in the house.