RESEARCH PROJECTS: PHYSICAL DYNAMICS OF COLLECTIVE BEHAVIOR
Honeybee fanning behavior
Honeybees actively drive airflow through their nests by fanning their wings at the nest entrance. This is a unique instance in which an insect uses its flight system for a non-flight function. I used high speed videography and particle-based flow visualization to quantify the kinematics of fanning behavior and the flows that it generates.
Colloborators: Nick Gravish and Stacey Combes.
Self-organized nest ventilation
Honeybee nests often have singular entrances. This means that fanning bees must establish inflow and outflow through the same opening. Using a combination of experiments and modeling, we discovered that honeybees responding only to local temperature are able to self-organize to separate inflow and outflow in space. This patterning arises from the interplay between fanning behavior, temperature and airflow.
Colloborators: Orit Peleg and L. Mahadevan.
Mechanical stability of swarms
Honeybee colonies form swarm clusters during reproduction. These clusters consist of a mass of ~10,000 bees which cling to each other and hang from a tree branch. When the tree branch is exposed to wind, it sways about and destabilizes the swarm. We shook swarms of bees using a linear actuator and discovered that the cluster can change its shape to stabilize itself in response to such mechanical perturbations.
Collaborators: Orit Peleg, Mary Salcedo and L. Mahadevan.
Concord Field Station
I started a small research/teaching apiary at the Concord Field Station in 2013 and have been managing it ever since. Many collaborative studies have benefited from the apiary over the years. The apiary has ~12 beehives, a weather station, a storage shed and power for automated hive monitoring studies. In 2015, we held an introductory beekeeping workshop for local high school teachers.
by bio-inspired robots
Honeybees fan their wings at the entrance of the hive when the temperature is above a threshold. Due to complex feedback with the airflow, bees are able to self-organize efficient ventilatory airflow in which in/outflow are separated in space. I developed a multi-agent robotic model of this system with Jim MacArthur. We demonstrate that analog robots following simple rules can achieve similar ventilation behavior even without a central controller.
Collaborators: L. Mahadevan and Jim MacArthur.
Collective thermoregulation in
Honeybee swarm clusters are also exposed to extreme ambient temperature fluctuations in the spring. Experiments have shown that swarms regulate their density to control how much heat they dump to the environment as ambient temperature changes. I built a temperature-controlled room and a 3D scanner to quantify the dynamics of this thermoregulatory morphing behavior.
Collaborators: Orit Peleg and L. Mahadevan.