A bed bug’s life begins with an egg, grain like and milky white in color. Female bed bugs lay between one and five eggs each day and may lie up to 500 eggs within one lifetime. Eggs are laid singly or in clusters and are placed within tight cracks or crevices. The egg is approximately 1 mm in length and is comparable in size to two grains of salt. Within two weeks, eggs hatch and immature bed bugs begin immediately to feed.
These young bed bugs, or nymphs, pass through five molts before reaching maturity. Although nymphs appear similar to adults, they are smaller in size and are not yet sexually mature. Young nymphs are also yellow-white in color, while older nymphs and adults are reddish-brown. In order to complete a molting stage, each nymph requires a blood meal. At room temperature, nymphs molt and become adults within five weeks.