I have my hive set on a iron pole about 2 ft off the ground, with a oil trap around the pole to keep out unwanted pest like ants. But all I have on the bottom of my hive is a screen bottom, I mean I can get down under the hive and look up and see though the screen what is going on in the hive. My question is this going to be OK to leave it this way this winter open on the bottom or should I put something underneath the hive to keep out draft and maybe a little of the cold. The colony is not very big at all, and I noticed that a few of the bees were already dead on the bottom of the screen. Need a little advice. Thanks