Bed bugs start off as little white eggs that are about 1/16th of an inch long.
Recently hatched bed bugs (nymphs) are as small as a pin head and are a translucent white. once they feed, their abdomen will look scarlet red for a little bit until the blood turns black. As the Bed Bugs grow, they will shed their exoskeleton (exuviae), become larger, and become more and more reddish-brown until they reach adulthood.
The exuviae look just like bed bugs but is just an empty shell that is a translucent amber color.
Adult Bed Bugs are a little smaller than the size of the nail on your pinky finger. They are reddish-brown with an almost flat oval body, short antennae, and have six legs. Two legs point forward while the other four legs point toward the rear of the bug. Bed bugs that have not fed in a while will be lighter in color with a dark spot running down the center of its body while newly fed bed bugs are much darker in color and are more of a football shape due to the ingested blood. Females have a rounded body while the males are more oblong and have a pointed rear end.