Many describe honey bees as a “superorganism” because thousands of bees function as a single unit. These thousands of bees perform several tasks for the betterment of the entire colony, including foraging, defending, brood caring and cleanliness for the entire colony. Each bee has their own task or role within a colony, and they must execute it for a colony to truly thrive and survive. However, in order to operate a highly-functioning organism, each bee must properly communicate and perform a panoply of behaviors. For example, colonies display hygienic behavior as a way to defend the colony from various brood disease. This is just one example, and washboarding may be another.
Honey bees washboard for no apparent reason, which is fascinating considering humans have kept bees for several thousands of year. In reality, washboarding is an understudied behavior, which is perplexing because honey bees are a model for group behavior among scientific circles. When I say model for group behavior, I mean scientists study honey bees to understand social behavior and how groups arose. In short, honey bee behavior is highly studied! So why do we not know what washboarding it?
Before I explain why, I must describe washboarding. Washboarding honey bees look almost like they are bearding, yet they look much different than bees bearding. These bees gather outside the colony (but can bee seen gathered inside), and they rock back and forth. They seem to be lined up in rows, and spread across the face of the colony. The washboarding bees move their front legs frenetically back and forth, as if they were “scrubbing” clothes, thus the name washboarding. Some folks describe the washboarding behavior as a sweeping behavior because they move their front legs back in forth in an almost rhythmic movement. It is quite odd, so check out the video on my facebook page . I would add it to this blog but I cannot due to payment requirements. Ask to add to join the page to watch the video! But, many washboarding videos do exist online.
Washboarding was studied by Jeff Pettis of the USDA and Katie Bohrer. They believed washboarding was performed as a sort of general cleaning behavior, but the evidence does not point to that direction. But when they observed it, they found a few things:
- Many wasboarding bees were between the ages of 15-25 days, with an average age of 13 days old.
- The behavior was most prevalent between 8:00 to 2:00 pm, but the behavior was observed at 9:00 pm.
- The behavior increased as the texture of washboarding surface increased. The researchers found that washboarding was more prevalant on rough surfaces like wood and slate, but less prevalent on smooth surfaces such as glass.
These were observations from the scientists, but beekeepers have anecdotal explanations for the behavior. Most beekeepers believe honey bees washboard immediately after a major honey flow, which is when it is often observed. While washboarding does seem to be associated with general cleaning, most research is needed to support this claim. I observed washboarding recently, on May 30th to be exact in Jamestown area ND. I talked to several commercial beekeepers in Minnesota, and they observed washboarding the same day. North Dakota and Minnesota have very different honey flows, so it may be due to a photoperiod or temperature cue. I have really only observed it in Late-May to Early-June, so this is my observations.
Washboarding is a very cool behavior, even though the function or purpose is unknown. Washboarding is one of the greatest mysteries of honey bees and I look forward to future research on the subject. Honey bees use behavior for a wide variety of reasons, and washboarding may be a necessary behavior for the survival of honey bee colonies. Either for the protection from pathogens and diseases, or as a signaling/communication cue. When I observed it, the bees seemed to be releasing a pheromone based upon what I smelt. But who knows… Hopefully this phenomenon will be solved soon so we can understand this fascinating behavior!
I hope you enjoyed