bee biology

Why honey bees collect propolis

Although we say honey bees collect propolis, what they actually collect are the materials to make propolis. The substances the bees bring home are sap-like resins exuded from flower and leaf buds. For the plants, these resins form a defensive coating, protecting delicate plant parts from pathogens, fungi, and insects. Foraging honey bees scrape it off plants and carry it in the pollen sacks on their hind legs. It often looks like a load of pollen except that it glistens in the sunlight and is usually a rich chestnut brown. Once home, the bees mix the resins with saliva and beeswax. The final product is what we know as propolis.

The color however varies with the source. It may be a whitish gray, tan, a variety of browns, or nearly black. Its composition also varies considerably, and so do its antibacterial and antifungal properties. As a general rule it averages about 50% balsams, 30% waxes, 10% essential oils, and 5% pollen. The rest is a vast composite of amino acids, vitamins, and minerals.

Propolis has many purposes

Bees use propolis for a number of purposes. They tend to seal small cracks with it, they use it as a polish on the inside of brood cells, and they wrap dead things with it to prevent putrefaction in the hive. Dead mice and snakes—which are too big for the bees to remove—have been found completely sealed in propolis, much like a mummy. They also smear it over rough places in the hive to reduce wear and tear on their delicate wings, and sometimes will use it to reduce the size of their entrance.

As any beekeeper knows, they also use it to seal the frames to the brood box, the boxes to each other, the boxes to the bottom board, the roof to the inner cover, the inner cover to the supers, and on and on. Hence the invention of the “hive tool”—a creatively-named implement that allows the beekeeper to pry, cuss, and moan until the hive comes apart.

From sticky to brittle

When warm, propolis is gooey, stings into ropes like hot mozzarella, and is incredible sticky. When cold, it is brittle and will snap like glass. Regardless of the temperature, the bees move it to irritating (for humans) places. It is for this reason that some breeders have selected against propolis collection and have produced a few genetic lines that collect considerably less than others. As often occurs after human interference, there is now some question about whether these bees can adequately defend their hives against pathogens.

This honey bee is carrying a load of plant resins on her hind legs. Back at the hive it will be turned into propolis.

This honey bee is carrying a load of plant resins on her hind legs. Back at the hive it will be turned into propolis. © Robert Lunsford.

Honey Bee Suite


  • Hi Rusty,
    I love your site. I come to it all the time to help answer my first year beekeeping questions and I am sure I will continue to come to it to stay informed. Will bees use propolis that I have scraped off frames from a super I am not leaving on the hive? You said they will move it so if I leave what I have out on their front porch will they use it and will that be helpful for them? Thank you for all you do here!

    • Krista! What a great question! I love it when someone sends me a post idea, and this is a good one. But for now, I’ll just say that the word “propolis” seems to be reserved for the stuff honey bees collect. However, some other bees, known as resin bees, do collect sticky plant exudates to use as building materials. Most of these bees are in the family Megachilidae. Along with other builders like the Osmia, leafcutters, and woolcarders, they use their findings to line their nests or build partitions.

  • I recently attended a local meeting of the Northern Illinois Beekeepers Association. During the meeting it was mentioned that bees use propolis to stay healthy as well as for all of the things you listed. One member said he read that if you scar up the inside of your hive body they bees will have more areas to repair with propolis so more will be available for their health reserves. What’s your opinion on this theory? I’m brand new to beekeeping, I should get my first bee order in a week or so and I can’t read enough on them. That said your site is an amazing resource that I’ve shared with many beekeepers.

    • Tom,

      Perhaps that is true, but it is also dependent on the race, the genetics of your particular hive, and how much propolis is available.

  • I am a hobbyist bee keeper. I have had the hive for over 2 years and I am still perplexed by bee behavior. Currently, I have observed bees carrying pollen landing and entering the hive. A few seconds later, same bees fly away with pollen baskets still full. What is going on?

  • Hi Rusty- I went into one of my hives this weekend and noticed that they stopped using the bottom deep (there is brood in the second deep and the first medium, honey is at the top). However there was a ton of propolis in the bottom deep; it was more than I’ve ever seen in other hives! Do you think they are getting ready for the fall or protected themselves from something? They hive was very docile until I got to that deep- then they were upset with me. My plan was to reduce the hive and get rid of that deep- but perhaps they have a plan and I should let them bee? Any advise would be helpful!


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