We have been dealing with mice since the fall, eventually we got a pest control company and their recommendation after setting their baits for ~3weeks is to seal all the cracks and holes.
One thing they mentioned though was to grate the bathroom and dyer ventilation. We use since our dryer vents through the attic we installed this vent
which opens and closes when the dryer is running, however the pest control company insists it's one of the ways they are coming in and we need to grate it. I'm a little concerned about that since dryer lint can get stuck in there and cause a blockage, and frankly i'm not even sure how mice can get into that type of vent. What do you guys think?