The sex determination in honey bee is based on the number of sets of chromosomes an individual receives.

An offspring formed from the union of a sperm and an egg develops as a female (queen or worker) and an unfertilized egg develops as a male (drone) by means of parthenogenesis. This means that the males have half the number of chromosomes than that of a female.

The females are diploid having $32$ chromosomes and males are haploid i.e. having $16$ chromosomes. This is called haploid diploid sex determination system and has special characteristic features such as the males produce sperms by mitosis, they do not have father and thus cannot have sons but have grandfather and can have grandsons.