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.
Anatomy of a male ant. The only time youâll encounter a male ant is during mating, because they die shortly afterward. Like queens, males have wings and muscular mesosomas for flying. But males are typically not as large as queens and have smaller heads with bigger eyes and straighter antennae.