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.
A queen ant is an adult, reproducing female ant in an ant colony; generally she will be the mother of all the other ants in that colony.Some female ants do not need to mate to produce offspring, reproducing through asexual parthenogenesis or cloning, and all of those offspring will be female. queen ant is an adult, reproducing female ant in an ant colony; generally she will be the mother of all the other ants in that colony.