Cleansing Flights

Cleansing Flights
Reading Time: 5 minutes

Did you go to the bathroom today? Was it a simple task to walk to the loo, shut the door, and take a moment in relative peace? Or was it more like a mad dash to the nearest facility with little control over where everything landed? If you said “yes” to either of these scenarios, then you have a good idea of the honeybee’s version of a bathroom break. Known as cleansing flights, these brief departures from the hive allow the honeybee to void herself of fecal material. And as with other living creatures, the “outcome” of cleansing flights can be a helpful tool in determining overall colony health and hive conditions, allowing the attentive beekeeper to make informed management decisions. 

Cleansing Flights 101 

Cleansing flights are nothing fancy, biologically speaking, and usually never give cause for alarm. Typically conducted on a warm, calm day, bees take their cleansing flights and drop their loads far enough away to avoid soiling their own home, so many beekeepers never even notice when their bees take cleansing flights. 

However, when you notice feces from a healthy colony, it’s not usually on the hive or inside it. It’s decorating anything you don’t want sticky bee poo stuck to — sidewalks, porch decks, yard umbrellas, even children playing outdoors — true story! You’ll know that unsightly mess is bee frass because it will be yellow to brown, appearing as dots or long, tube-shaped pieces of incredibly sticky fecal matter that hardens into a nearly impenetrable object. 

Winter and early spring cleansing flights are the ones that most often raise alarm bells. The results of these cleansing flights are a bit more evident, with the telltale signs often being a speckling of those yellow/brown dots or streaks in the snow on the ground just outside the hive. To make the alarm bell sound even louder, these perfectly normal droppings are often accompanied by a few dead bees lying in the snow as well. Some of these dead bees will be victims of the cold as they took their cleansing flights, while others are simply dead bodies tossed to the wayside during hive cleaning duties. All these signs are everyday aspects of hive cleanliness, as bees prefer to keep their home tidy and clean, free from feces and dead bee carcasses.  

When It Goes Wrong 

While bathroom breaks are usually uneventful, a colony in distress may show its compromised condition via cleansing flights. A healthy bee can hold between 30-40% of her body weight in fecal material before she is forced to defecate. To put that into perspective, a 150 lb. beekeeper holding 40% of his body weight in human feces would feel quite stuffed at a whopping 60 pounds of poo residing within his now seemingly tiny body. That’s a lot of pressure!  

Now, imagine you’re a bee that needs warmth to enable you to fly to the bathroom. But it’s winter, cold, windy, and maybe even raining, snowing, or freezing rain. How are you going to go? You’ll freeze to death before you make it to the landing board. So, you hold it. And wait. As the cold days drag into what seems to be oblivion, that 40% now feels like 100%. 

Finally, on the first warmish day that reaches close to 50ºF with little to no wind, you work your way towards the exit through the warm cluster that’s slowly breaking with the warmth of the day, wiggling your wings in anticipation. Then, you let it all out without ever taking flight. If you were fortunate enough to make it to the landing board or the upper entrance, you might consider your trip a success despite leaving behind streaks of yellow down the side of the hive body or the landing board. If not, then the house bees will now have to clean up your mess inside the hive. Not a good day, for sure. But you’re not technically sick; it’s just been too cold to get out to the bathroom. So now you are exhibiting signs of diarrhea — a.k.a. dysentery. 


Dysentery, or diarrhea, is often confused with the human form of dysentery and the honeybee infection known as nosemosis. In humans, dysentery is caused by bacteria, parasites, chemicals, etc., and is not dysentery that bees exhibit. The microsporidian parasite Nosema apis causes nosemosis, and resultant diarrhea is indistinguishable from dysentery without laboratory testing.  

On the other hand, pathogens do not cause dysentery in bees but rather a combination of lousy flight weather and too much ash, or solids, in the food stores. However, dysentery may open the door to secondary infections that can be fatal to the colony under the right conditions. So, while dysentery is not technically a disease but rather a symptom of other issues, it’s still a good idea to implement a few management practices to help the bees better navigate the difficulties of limited winter cleansing flights.  

How to Help 

It is possible to alleviate hive conditions with a little bit of planning:   

  • Add upper entrances — With no upper entry, bees must travel down through the cluster into the cold space beneath, leading to the even colder bottom entrance. This cold rapidly chills the bee before she makes it to the landing board. If she is successful, she must still move back through the cold to return to her cluster if she doesn’t freeze to death first. Upper entrances, however, can facilitate cleansing flights by allowing bees to travel UP through a warm cluster and UP into a warmer upper hive area to an entrance warmed by the flow of warm air emitting in an upward fashion from the cluster. This reduces the amount of chilling a bee undergoes during her trip to the bathroom. 
  • Remove dark honey — While most agree honey is the best food for bees, the extra solids found in dark honey are the primary culprit in honeybee dysentery. Because the extra roughage adds additional material to the bee’s gut, the water the bee ingests causes the roughage to swell, increasing her overall load of material that needs to be released. Beekeepers often remove dark honey in the fall and replace it with combs of light honey or utilize white sugar blocks, sugar syrup, and high-fructose corn syrup (as temps. allow) as alternatives that offer less roughage.  

While cleansing flights are typically non-eventful, an observant beekeeper can take what the bees show them during their bathroom breaks and learn a little about the colony’s health. Most often, cleansing flights are sufficient to keep the colony healthy and thriving. Other times, dysentery appears, alerting the beekeeper to insufficient cleansing flights and the possible need for minor intervention — or the possible need to test for nosema in more extreme cases. So don’t overlook this tiny detail in the bee’s day-to-day activities, as you might miss a little note regarding the colony’s health. 


AUTHOR’S NOTE: These two photos are the only two I have displaying dysentery as my hives have had minimal issues with this condition. However, if you enlarge each on you can see streaks in one and spots in the other, though both are very mild. 

Originally published in the December2021/January 2022 issue of Backyard Beekeeping and regularly vetted for accuracy.

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