Drones need more time to get so much larger than workers. To attain this growth, they get an extra 3 days to develop as pupae, for a total of 24 days from egg to emergence as an adult, compared to a worker’s mere 21 days of development. Also, they aren’t just larger than workers; some individual drones weigh more than some of the smaller individual queens. Drones can have bodies as wide as or even wider than queens, particularly in the abdomen, even though they are not as long as queens.
Note: Still, queens are larger on average than drones in the honey bee world. .