Glass will not allow excess moisture to disipate out the top of the hive with excess heat. The result will bee moisture dripping from the glass inner cover onto the bees. This will increase the incidence of disease, mold , mildew and could cause ice to form inside the hive in extremely cold weather. It will also make the hive more susceptible to winter kill. If you want a cheap inner cover, use a piece of cotton cloth. If you want a see through inner cover, I suggest you use less smoke and open the hive very slowly. ______________________________ Reply Separator _________________________________ Subject: Inner covers Author: Discussion of Bee Biology <[log in to unmask]> at internet-ext Date: 9/8/96 8:36 PM I would like to know what the pro and cons are of inner covers, that are made of glass.