Sneaky, underhand and generally distasteful: Stylops flies do not lead fulfilling lives. Small and black with membraneless wings, males are the only ones blessed with flight. The females are condemned to a life as little more than a reproductive tract with a mouth. They are obligatory endoparasites that live in the abdomens of solitary bees such as Andrena scotica, the chocolate mining bee. Other species inhabit other insects such as grasshoppers and dragonflies. While males begin life in the abdomen along with the female, they soon emerge. The males now fly around to find other bees which have been stylopised. Once found they will land on the bee and proceed to stab their adaegus (penis) in to the reproductive tract of the female, through her exoskeleton. This brutal technique is known as traumatic insemination and will eventually kill the female from excessive damage or disease. However, before this happens the bee will land on a flower and the female stylops will lay hundreds of eggs into the flower. The eggs will mix with the pollen and the next time a bee visits the flower it will take up the eggs too which will eventually hatch, worm their way into the bee’s abdomen and start the cycle again.