Hive management in early spring to speed up brood production. Propolis is another byproduct of the bee hive. Certain races of bees are more prone to using propolis. Propolis can be collected on special plastic propolis screens. The tendency of the bees is to use propolis as a glue to seal openings that are too small for a bee to crawl through. A propolis screen is usually put in place of an inner cover. It has small openings that are propolized by the bees. The propolis screen can be frozen which hardens the propolis. Once the propolis is frozen it can be
Animal glue less. In practice, this often means having to heat the pieces to be glued, and gluing in a very warm room, though these steps can be dispensed with if the glue and clamp operation can be carried out quickly. Where hide glue is in occasional use, excess glue may be held in a freezer, to prevent spoilage from the growth of microorganisms. Hide glue has some gap filling properties, although modern gap-filling adhesives, such as epoxy resin, are better in this regard. Hide glue that is liquid at room temperature is also possible through the addition of urea. In stress