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.
Little black ants are small and dark-brown, black or jet black in color and are a native species found throughout the United States. The workers are as small as 1.5 mm in length, and queens can measure up to 4 mm. Their antennae consist of 12 segments and end in a three-segmented club. Their pedicel, or the ant waist, is two-segmented. Little black ants have no spines, and their thorax is unevenly rounded.