Perforated Cable Trays Vs Rodents

I used to be a beekeeper, it is accepted by beekeepers that mice will squeeze through a 10.0 mm slot. as they have flat skulls and can flatten themselves down, so a 25.0 mm X 10.0 mm slot is not a challenge, they will be in like Flynn.

Bee hive mouse guards generally have 10.0 mm holes, but as Graham said some people think a young mouse will still get through those 10.0 mm holes and prefer 8.0 mm holes, which is still big enough for a bee to get through, but may scrape the pollen they have collected off their legs.

easy-beesy.com/whats-the-correct-beehive-mouse-guard-hole-size-and-how-to-make-one

I used to be a beekeeper, it is accepted by beekeepers that mice will squeeze through a 10.0 mm slot. as they have flat skulls and can flatten themselves down, so a 25.0 mm X 10.0 mm slot is not a challenge, they will be in like Flynn.

Bee hive mouse guards generally have 10.0 mm holes, but as Graham said some people think a young mouse will still get through those 10.0 mm holes and prefer 8.0 mm holes, which is still big enough for a bee to get through, but may scrape the pollen they have collected off their legs.

easy-beesy.com/whats-the-correct-beehive-mouse-guard-hole-size-and-how-to-make-one

Interesting past-time: I used to help a friend with his bees.

Clearly there are no obstacles to rodents in older loft spaces - I was up there today sorting out redundant cables and there was plenty of evidence of occupation. How do domestic sparks cope with that day in, day out?

I am curious to know: do modern pressure tested houses leak enough to let rodents in?