This goes on the Bottom Board and makes the entrance to the hive smaller. The bottom

board is just a doorway, it is no door. If your house had no door you would probably

guard the doorway to your house so that not just anyone could walk into your house but

if your doorway was very big you might have trouble guarding it. This is the same with

the bees, if the “doorway” is too big for a smaller colony to guard they will struggle so

don’t hesitate to use an entrance reducer.