All hives have to have a bottom board. I am pretty sure it keeps the bees from falling out. Hmmm, I'm not sure. I'll have to check with Mr. Bill. Anyway, he gave us a regular bottom board, and a friend gave me a different bottom board that has the natural Diatomaceous Earth in it. They are called Beetle Busters, and I hear those things are expensive! They are like one hundred dollars each! But she gave it to me for free, and it looks very nice. I like it. I can't wait for my bees to come so I can use it! I am so excited!