 After the emergence of the first or second group of offspring , workers take over the task of foraging and the queen spends most of her time laying eggs and caring for larvae . The colony grows progressively larger and eventually begins to produce males and new queens . Unlike the workers of more advanced social insects such as honeybees , bumblebee workers are fertile , and can lay unfertilised haploid eggs ( with only a single set of chromosomes ) that develop into viable male bumblebees . Only fertilised queens can lay diploid eggs ( one set of chromosomes from a drone , one from the queen ) that mature into workers and new queens . 
