Bed bugs, also known as Cimex lectularis, feed mainly off of human blood. Bed bugs are flat bodied, oval shaped and a reddish brown color. They secret an oily, unpleasant-smelling substance. This substance secrets from two glands located on the insects underside. They can survive a year without feeding. These insects are largely nocturnal. They spend the day in crevices in walls, furniture, bedding, mattresses, box springs, bed frames and headboards. Their bites cause small welts and itching.