Mouse in ceiling

Hello,

from time to time I have a mouse in the ceiling. This started several years ago after we had a new deck installed. After having professional exclusion services and a whole lot of expandable foam the problem stopped. Just recently it began to start again. I have a camera in the ceiling and about one every couple of weeks I catch a mouse. They are always in the same spot. The basement is finished and the only access I hav to the ceiling is for the water shut off. I’ve crawled under the outside of the deck multiple times and always spray foam and peppermint and still see the occasional rodent. I also found one in the Window well by the basement. Since then I’ve packed the well closed with small pebbles and covered it with a dome. My guess is that when the deck was installed a small hole was made that I keep on missing. Any suggestions? The mouse seems to drop down the back and comes around to the front of the camera. There is insulation up there that blocks most of the view when I point the camera ups the hole in the ceiling is too small for me to get my body inside. I love in an attached townhome.

 

The building of the deck and rodent entry could just be coincidental, have to keep that in mind when looking for solutions.

Did/does the exclusion contractor offer a warranty or follow-up service?

Is there an attic in the townhome, and if so, is there any access to inspect? Did the exclusion contractor go in the attic, if there is one and is accessible? The attic, or roof space would be attached to a neighbor, maybe two neighbors. That could be access for mice. Can you talk to neighbors to learn of their rodent experience? I suspect that the townhomes share the same exterior covering/siding over the common exterior walls so there will always be compromises with exclusion in attached structures. Not a good answer, but it's the reality.

The interior perimeter walls of the townhouse are also attached to neighbors on at least one side if not two, and there is a lot that is inaccessible and not visible to occupants and never will be. This is difficult, if not impossible to overcome.

Did I understand correctly that you filled the window well with pebbles, bottom to top? If so, I see more negative than positive results in that. Weight and pressure on the window would concern me. Maybe I misunderstood though.