Bed bugs have small, flat, oval-shaped bodies brown in color have six legs, although their bodies redden after feeding. Full-grown bed bugs move relatively slowly and measure between 4 to 8 mm. Newly hatched nymphs are approximately the size of the head of a pin and are white or tan until they feed. They often are described as being about the size and shape of an apple seed or rice grain.When you look at an unfed bed bed, they appear round but after a good feeding, their bodies elongate to contain the blood and turn reddish-brown in color and about the same size as a lady bug.Although bed bugs are hard to find, they leave tell-tale signs such as odor and bites with the biggest sign being little black dots(their cast skins from empty shells and blood meal fecal spots composed of digested blood ) on your sheets or mattress.