The bed bugs are a type of chestnut-brown insects which have a flat shape from top to bottom. The size of the adult bed bugs is around 1/4th inch in length. The bed bugs are found to grow multiple numbers of times by a process termed moulting. The baby bed bugs are known as nymphs and they resemble the adults in every way. The size of the nymphs is much smaller than the adult bugs. The nymphs require a total of five moults to metamorphose into the adult bugs. In each phase of this metamorphosis, the bed bug must feed on a blood meal to convert into the next phase. Though the adult bug can feed only once in a week; the nymph has to feed on blood meal several times during their four-month-long life-cycle.