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.
Carpenter ants are the largest of the house-infesting ants. Workers within the colony range in size from about 3/16 to 5/8 inches in length. Color varies among species, although black seems to be predominant. Carpenter ants, like termites, tend to prefer wood that is partially decayed by wood rot.