Megalopta genalis is a species of the family Halictidae, otherwise known as the sweat bees. The bee is native to Central and South America. Its eyes have anatomical adaptations that make them 27 times more sensitive to light than diurnal bees, giving it the ability to be nocturnal. However, its eyes are not completely different from other diurnal bees, but are still apposition compound eyes. The difference therefore lies purely in adaptations to become nocturnal, increasing the success of foraging and minimizing the danger of doing so from predation. This species has served as a model organism in studies of social behavior and night vision in bees.