Honeybees and their jobs

Every honeybee has a job to do. Some are nurses who take care of the brood; some are janitors who clean the hive; others are foragers who gather pollen to make honey. Collectively, honeybees are able to achieve an incredible level of sophistication, especially considering their brains are only the size of sesame seeds. But how are these jobs divvied up, and where do bees learn the skills to execute them?