Look at the bottom of the hive stack and can you see the metal circular holes?
These small holes let in bees but not the invading mice. To animals and mice alike the beehive is like a veritable supermarket full with shelves of food. This hive stack is now prepared for winter. When the bees are asleep mice would love to come in and restock their nests for the winter famine. We have to keep them out otherwise our bees would soon find all their hard earned winter food removed.