Using 1/2" wire mesh on any openings will work for rats. Mice are near impossible to keep out of anywhere. They can squeeze through the tiniest gap.
As others have said make sure they can't get at the feed. If there is nothing for them to eat they will go look elsewhere. If they can eat there they will stay and breed quickly.
It is a pain but make sure they can't feed and you won't have many problems.
As @RobertSWMissouri says, don't have places for them to hide. The chickens will eat mice if they can get at them!
Dogs and cats can help. They usually can't get all of them but they scare a lot away.
I like breakback traps for rats. Scaled up mousetraps. Bait them with peanut butter and put them where the chickens can't get to them.
As others have said make sure they can't get at the feed. If there is nothing for them to eat they will go look elsewhere. If they can eat there they will stay and breed quickly.
It is a pain but make sure they can't feed and you won't have many problems.
As @RobertSWMissouri says, don't have places for them to hide. The chickens will eat mice if they can get at them!
Dogs and cats can help. They usually can't get all of them but they scare a lot away.
I like breakback traps for rats. Scaled up mousetraps. Bait them with peanut butter and put them where the chickens can't get to them.
