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.
How do you know if the ant is a female or male? Is a drone a male ant?   yes the drone ant will look just like the queen they both have wings but unlike the queen the drones wings are permanint. the only purpose of the drone is to mate with tâ¦he queen and after the drone will fly away and soon after will die.