A Nuc box is box that hold a nucleus colony, like a queen and about 1000 bees. Beekeepers use these for catching swarms or removing extra bees from an overcrowded colony. I don’t have extra bees in my hives but I did recently catch a swarm. If I catch another one, I’ll use this Nuc to hold the swarm to either replace a weak hive ( I have one of those) or start over. Besides, Nucs look really cool and a lot easier to make than a full hive. I painted mine today. Five frames ready to go!