Propolis is a substance produced by bees from substances gained from
budding leaves and plant and bark resin and secretions. To this
material bees add their pollen and beeswax, mixing it using their
saliva. It is a substance they use to cover the entire honeycomb,
protecting its inner environment. It is used because of its
impermeability and thermal isolation capacity.

It has the added advantages of being a natural antibiotic, bactericide
and fungicide. It assures a sterile environment within this part
of the hive. It is rich in flavonoids (antioxidants).