Varroa-Nator Screened Bottom BoardAnother tool in your kit to control Varroa mites. This Screen Insert is made of very durable, temperature tolerant molded plastic with stainless steel screen. Can be used in conjunction with your existing bottom board (remember to reverse the existing bottom board, so the bees don't get stuck between the two), or as a warm weather bottom board. The mites will fall through the screen and are not able to get back into the hive.