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.
Swarmers, winged male and female ants who are born in the Spring in order to mate are also about 3/4 inch. Carpenter Ants are one of our most common ants. They are found in dead wood, such as trees, fallen logs, stumps, or even in houses. Carpenter Ants are mostly black, usually ranging from 1/4 inch to 1/2 inch.