The BVD stands for Back Vertex Distance, this is a measurement that is included on any prescription where the sphere or cylinder powers are higher than + or - 5.00D and to a lesser extent some prescriptions where it is less than this power.
Winged Drone | Alate | Male Ant. Drones are the only male ants in a colony. They are born from un-fertilized eggs. Drones are not like typical ants. They donât do any work in their nests, and they look more like wasps than ants. They are reproductive winged ants and so are alates.
Flying Ants. Whether the winged ant you see is a carpenter ant or a termite, however, the wings mean that the insect is a reproductive male or queenâthe only members of an ant colony that can reproduce.ome carpenter ants are much larger than termites. In fact, carpenter ants are one of the largest of all ant species! But other carpenter ants are very small, so size is not a way to determine species.