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.
Ants live in colonies where one or a few females, called queens, lay all the eggs. Most of the queens' offspring become worker ants that do not reproduce. A few are males, and some become new queens.Each queen ant can lay thousands of eggs per year.nts are skinny insects. Like their relatives the wasps, they have a narrow connection between their abdomen and thorax. They have chewing mouthparts, and their antennae are bent in the middle. Some ant species are very tiny (1-2mm long), but some tropical species are very large (30 mm).