Table of contents
We’ve all seen honey bees fly in the rain. A light sprinkle or a short shower seems to have little effect on a foraging bee. On the other hand, a storm with heavy rainfall will keep the bees inside their hive. How do the honey bees decide when it’s safe to fly?
Based on a number of studies and a lot of anecdotal evidence, we know that honey bees are good at predicting the weather. In fact, honey bees seem to be more accurate than The Weather Channel when it comes to predicting rain. Not only can they predict it, but they can estimate its intensity. That is why a light drizzle may not influence their foraging patterns, but a heavy storm can keep them home.
Bad weather can trigger defensiveness
In a paper entitled “The Effects of Meteorological Factors on Defensive Behaviour of Honey Bees”1, researchers found that honey bees are more defensive during the approach of bad weather. The authors found that these spikes in defensiveness were largely the result of meteorological factors, including temperature, humidity, amount of solar radiation, wind speed, and barometric pressure.
Some beekeepers speculate that this increased defensiveness occurs because the bees “know” they must protect their food stores for the lean times ahead. Since honey bees are always “mindful” of the future, they increase the defense of their food stores.
Bees work harder before a storm
In a more recent study, “RFID Monitoring Indicates Honeybees Work Harder Before a Rainy Day”2, researchers tagged honey bees with RFID devices in order to track their foraging activity. They found that honey bees spent more time foraging on days immediately before a significant storm. Furthermore, they found that honey bees worked later into the evening the day before a storm. Their theory is that the bees “predict” that food will be in short supply during the stormy weather, so they work extra hard before the storm hits.
These researchers point to prior studies, such as the one on defensive behavior, and speculate that honey bees predict the weather based on temperature, humidity, barometric pressure, and carbon dioxide levels. Many animals are able to predict inclement weather, just as we humans often do. We say things like, “Feels like rain” or “Smells like snow,” probably due to similar environmental signals.
My own anecdotal evidence: bees under a sprinkler
Last year I inadvertently tested this theory with a lawn sprinkler. On a hot and sunny July afternoon, I decided to water the lawn next to one of my hives. I set up a sprinkler which rained down on the hive and the surrounding grass. By all appearances, the bees were unperturbed by this turn of events, coming and going with pollen and nectar as usual. Even the accumulation of water on the landing board did not seem to upset them.
This type of observation lends credence to the idea that it is not the raindrops themselves that determine behavior, but the atmospheric conditions. When honey bees continue to forage during light showers and summer sprinkles, it is probably because the atmospheric indicators, the ones we can’t see, are telling the bees that it is safe to forage. “Get over it and keep working; there’s nothing to worry about!”
Weather-related behavior to watch for
In the future, I intend to watch their behavior more carefully. Do bees foraging in the rain mean the weather will soon clear, or at least not get worse? Do unusually high levels of activity on a dry day mean a storm is near? Do drones behave any differently? And how about other species? Now that I’m thinking of this, I can’t wait till spring.
Rusty
Honey Bee Suite
1Southwick, E.E. & Moritz, R.F.A. Int J Biometeorol (1987) 31: 259. doi:10.1007/BF02188929
2He, X.-J., Tian, L.-Q., Wu, X.-B. and Zeng, Z.-J. (2016), RFID monitoring indicates honeybees work harder before a rainy day. Insect Science, 23: 157–159. doi:10.1111/1744-7917.12298
I can tell your that bees do fly in the rain, I live where we get an average 72 inches a year (Oahu, HI) and some days it will pour all day. I can watch my bees with a spotting scope in my living room so I can see first hand when they leave and come back. Sometimes they will just cling to the trees or leaves until the heavy rain subsides and then back to work. We have flowering all year long so they are constantly bringing nectar and pollen which also allows me to gauge the growth of the colony based on activity. Maybe our bees are just adapted to our weather but rain or shine they are always working.
The Native Americans knew these things, back when. A lot of older rural folks used to know it too. They’d watch the animals for clues to predict the weather.
They have often been dismissed because they weren’t accurate all the time, with every animal. But the natives and older country folk knew to watch several animal.
Dogs get nervous, if there’s a thunder storm approaching. Cows will lay down in the pasture and sort of tuck themselves in. Birds will often go to roost early and in a more protected spot than usual. There are a lot more that I don’t recall at the moment.
If this is of interest to you, you might take a day trip out to the nearest reservation and chat with the older folk about it. They’re almost always happy to get the attention. 🙂
Then, you could see which things correlate with the scientific evidence that exists.
Craig,
I’d forgotten about the cows until you mentioned it. My grandfather used to predict the weather by watching the cows lie down in the pasture, and he predicted the direction of the storm by which way they were facing. The always faced away from it.
This is a very interesting topic.
And also partly linked to the answer is do they decide it’s safe to fly back at the hive or do they decide while out flying and alert the hive then? And do the bees make that decision as a group or which ones flip that switch?
I can’t say I am expert enough in bees to know the answer to this but it makes me curious.
With gnats and other flying insects if I put water on the garden they will go away for a while it seems. They will later go out again once the sprinkler is off.
With bees I’m not sure.
And if they do or don’t decide can they tell the difference between raining in one yard and not another?
Noah,
They are all good questions.
Very interesting stuff, Rusty. I want to share one of the most fascinating things I have seen the bees do relating to their instincts.
Last summer I was sitting outside watching them. It was about a couple of hours before dusk. The bees had been busy, busy, busy when all of sudden they disappeared into the hives in what seemed like a matter of seconds. They were not even poking their little heads out! I said to myself, what is going on? This really had my curiosity at high alert.
After about 15 minutes, the sky was darkened by thousands of swallows and just as many dragon flies swooping and diving in unison. The mosquitoes had been very bad last summer and the predators had moved in for the feast. The dragon flies were huge and swooped around my patio and my head. I would see a little mosquito and suddenly a dragon fly would nab it. It was amazing to watch the birds and dragon flies working together. When I realized what was happening, I’m sitting in my patio chair cheering them on. “Nail all of those blankity-blank-blank little blanks.”
This went on for about a week every evening and I knew when the bees totally disappeared into their hives, that the mosquito feast was soon to begin. It is truly wonderful what we can learn from nature just by taking the time to observe.
Bonnie,
That’s interesting. Do you think the bees were wary of the birds? Afraid of being eaten?
I can’t say if the ladies were afraid of being eaten by the birds or not. The birds did not come near the hives and remained at higher levels, but the dragon flies did not mind flying all around my head while scooping up their dinner. I was absolutely fascinated that the bees knew this was coming before a single swallow or dragon fly was seen for at least 15 minutes after all had safely tucked themselves away in their hives. The guard bees did not even appear at the hive openings to watch!
Hi. I’m Peter, located in London South East, UK. I am first year beekeeper;). My bees seem to fly in the rain very often. Given our weather pattern they would starve otherwise. I am very surprised to see them fly in the winter, but apparently it’s very normal here.
Originally I am Polish and back in Poland bees would not be seen out in December;) but London is different:).
Thank you for great source of information.
Peter
I really do LOVE your posts. I find the funniest thing about it starting to storm is the bees come into the hive like a bunch of 747’s dive bombing to get inside before the rains get hard, then, all the sudden, the hive will be quiet w/just a few protecting the entrance. All is well in the hive! Hope you had a very nice Christmas! The bees enjoyed the 68 degree weather around here. Was a nice break for them.
I have often wondered if I could assist the bees in winter by using a small solar panel and a 12 volt light bulb in the hive. Wrap the bulb so it doesn’t shine. Then on bright days there would be a small heat source.
Dave,
The problem with heat sources is always the same: If the bees are fooled into believing the outside temperature is warmer than it actually is, the bees may fly out, become stiff from the cold, and not be able to fly back.
Thank you Rusty! What an interesting article, and comments. I will observe my hives more closely and see if I can detect bad weather approaching. Best wishes to all for 2017!
Very interesting post I use to think the bees did not fly at all in rain. But I have seen them fly but more interesting was their activity before a storm as others have said. As a side note I use to watch cattle to determine if the fish were biting. It always seemed if they were up feeding the fish indeed were hitting. I don’t know why?
Wow, this is one of “those” bee questions.
To me, there are too many variables in the equation to come to a definitive scientific answer.
Yes, bees do fly in the rain, but I feel a lot depends on the current situation within the hive and it is also very dependent on genetics.
Genetics come in when say a colony has been bought in from a cooler climate, or an area with high average rainfall. Often when housed adjacent to local genetic strains, you will find these bees get up and get going earlier, stay out later and fly in more adverse conditions whilst the local bees stay hunkered up warmer and drier. A colony that were fair weather only bees may change if they are re-queened with a different genetic mix that makes them more determined to forage in light to medium rain.
Current situation within the hive counts, if the colony is light in stores, the workers will forage in more inclement weather. It is a needs must situation. Like when you realize during the holiday season you have run out of milk and need to pop to the store to get some, but it is raining outside. You put on a raincoat and go to the store so you can provide for your family. If you were a bee, you would be a queen, so you would wrap one of your children in a raincoat and send them to the store!
Then there is the strength of the rain. One mans downpour is another mans drizzle. I find if you throw strong wind in to the rain, it will cause the bee foragers to stay at home long before rain alone.
As for other animal behavior, cows will also sit down to digest their last meal and rest, doesn’t always mean rain when cows sit down.
For an interesting study though, try watching trout just before an imminent thunderstorm. They will circle a slow moving pool in an almost confused pattern and then sink to the bottom of the pool and sit almost motionless just before the first peel of thunder. A salt water aquarium used for fish studies not too far north of here have recorded instances of deep water species being held in tanks within the facility actually jumped from the tanks on to the concrete surround when a thunderstorm broke overhead. I guess they could not get deep enough to feel safe…….
Rusty
Bumbles certainly seem more poor weather tolerant. I’ll guess that it has to being being both furrier and bigger. I see bumbles foraging in colder weather, and earlier in the day than other bees. First generation workers, the smallest workers, sometimes specialize as nest attendants, and leave foraging as much as possible to bigger later generations. This bumble looks like a male, which may add to the explanation of it being out in the rain — where else to go.
Happy New Year. Good luck with your “comments” dilemma.
Glen B
PS My guess on bee behavior and storms is electric charge in the air. Maybe the static discharge changes and they no longer can pick up pollen — so might as well pack up and go home. GB
What a fascinating answer to my Googled question. I watch bees and lots of other things, all the time when walking my dog along the local river in the High Pyrenees. Thanks for what you wrote.
I observed something I’d never seen before. Both my hives had landing board full of bees, perfectly motionless, dead quiet. A few foragers straggling in. This was all morning, sunny hot. Then a huge storm rolled in quick. Seems like it was the perfect reflection of what the paper described. Creepy. I thought my queen died.