Honeybee males (drones) are haploid, while females are diploid.

As a result of this haplodiploidy, sister workers are related to one another by a coefficient of relatedness of 0.75, since they inherit the same alleles from their father, and share an r of 0.25 with their brothers.

The workers' r with to their nephews (their sisters' sons) is 0.375 if the queen mates one time, but can fall below 0.25 if the queen mates with numerous males.