Propolis is sometimes called bee glue.  Traditionally considered a messy annoyance by beekeepers, propolis is being researched more and more because of its healing properties.  Bees collect tree sap from coniferous trees and add other products to it when the bring it back to the hive.  Then it a thin layer of it is used to coat all the surfaces of the hive and larger amounts are used to fill in voids, cracks and “glue” everything together.

Beekeepers scrape off excess amounts and it is usually discarded.  Some beekeepers, like Two beekeepers make tinctures with it that do have medicinal purposes.  It does have a numbing effect on whatever it is applied to.