Rats like penguins, huddle for warmth and when they do, the collection of bodies acts like a self-organizing “super-organism.” The members of huddling mass rotate, so that outer rodants are brought into the warmth of the center before rotating back out. Rotation helps to regulate the group’s temperature so none become too hot or too cold. The rate of rotation varies depending on the external temperature. The huddled mass is able to change shape and retain heat. Therefore, the super-organism behavior is the product of a combination of collective selfishness and collective sacrifice. Each rat must sacrifice a bit of its own heat to ensure the group maintains a balanced temperature. Huddling models could help engineers designer improved super-organism-like robotics systems.
