This glue is used to seal hive cracks and holes. It is also placed at the entrance to the beehive, where incoming workers have to brush up against it as they enter the hive. This sterilizes the bees from infection, and may disinfect them upon entry as well.
Beehives are more sterile than the most modern hospitals.
Propolis is also used to line the birthing chamber where the queen lays her eggs, thereby providing a clean, sterile environment for the developing eggs. Of all the fourteen minerals the human body requires for normal function, propolis contains all but one, sulfur. It contains a number of unidentifiable compounds that create a perfectly balanced food substance. It is antibacterial, antiviral, antioxidant, antifungal, and anti-inflammatory. This substance has been used throughout many centuries for its natural antibiotic capabilities.