Honey Bees Self-Medicate with Propolis (IMAGE) North Carolina State University Caption When faced with pathogenic fungi, bees line their hives with more propolis -- the waxy, yellow substance seen here. Propolis is a combination of plant resins and wax that has antifungal and antibacterial properties. Credit Michael Simone-Finstrom, North Carolina State University Usage Restrictions Photo credit must be given License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.