Robotic ‘biohybrid’ systems help researchers study behaviour of finicky bees

The system is made of a combination of thermal sensors and actuators, and it measures and modulates honeybee behaviour through localised temperature variations.

“Many rules of bee society – from collective and individual interactions to raising a healthy brood – are regulated by temperature, so we leveraged that for this study,” Rafael Barmak, first author of a research article published on the system in the peer-reviewed journal Science Robotics.

According to Barmak, who is a PhD scholar at EPFL, the thermal sensors create a snapshot of the bees’ collective behaviour, and the actuators in the system allow the researchers to influence their movement.

Honeybees in winter

Unlike many other insects, honeybees don’t hibernate or go dormant during the winter. According to PBS, during winter, they create a “warm microclimate” inside the hive, and they live on the honey they have stored. The bees warm themselves and their nights by exercising. Yes, by exercising.

As a whole, the bees inside the hive exercise their flight wings or flap them without flying. Sort of like how a car engine can be warmed up by keeping the engine in neutral. The precious heat they generate by doing this is retained by the bees by allowing only small openings in the nest. They use plant resins and gums to seal holes and cracks. They then cluster into a round mass of bees.

The system is made of a combination of thermal sensors and actuators, and it measures and modulates honeybee behaviour through localised temperature variations. (Artificial Life Lab/U. of Graz/Hiveopolis)

By doing all this, they can keep the temperature at the outermost parts of the hive above 10 degrees Celsius. According to a study published in the Journal of Invertebrate Pathology, the predicted lowest temperature for the western honeybee is around 15 degrees Celsius. Below that, survival becomes hard for Man’s tiny friend.

Studying honeybees during winter using the robotic system

According to EPFL, previous studies on the thermal behaviour of honeybees in winter observed the bees by manipulating the outside temperature. But the new system allows researchers to change the temperature from within the cluster. This is closer to how bees actually behave during winter.

“Our robotic system enables us to change the temperature from within the cluster, emulating the heating behaviour of core bees there, and allowing us to study how the winter cluster actively regulates its temperature,” said study co-author Martin Stefanec in a press statement. Stefanec is a PhD scholar at the University of Graz.

Bee colonies are already difficult to study in the first place. But studying them during winter is even more difficult because they are sensitive to the cold. But using the new robotic systems, they were able to study three experimental hives located at the University of Graz in Austria, while controlling them remotely from EPFL in Switzerland.

Using the robotics system, the researchers gathered information about the bees’ locations in the hive, and they were able to encourage the bees to move around by using the actuators Bees don’t usually do much of that during winter, when they prefer to huddle together to conserve energy.

In essence, the researchers were able to act on behalf of the colony. For example, they could direct the bees towards food sources. Interestingly, the researchers were able to prolong the survival of a colony after its queen bee died by redistributing the heat in the colony using actuators.

According to the researchers, such “biohybrid” systems that open the door can potentially be used to help bees survive better. This could prove especially useful in a world where populations of important pollinators like bees are facing a crisis, which could have massive food security implications.