Bedbugs develop through a process called gradual or simple metamorphosis. Insects that develop this way do not change very much as they mature. In the case of bedbugs, the immature insects look very much like the adults.
Gradual metamorphosis has three stages: egg, nymph, and adult. Temperature seems so affect the development time of bedbugs. At 86°, bedbugs can complete the process in about three weeks. At 65°, the process takes almost four months.
The first stage of the bedbug's life cycle is the egg stage. The female bedbug deposits one or two eggs every day. She places the eggs in crevices where they will be undisturbed.
Bedbug eggs are tiny and white. Most people need a magnifying glass to see them. When they hatch, the immature bedbugs are about the size of the head of a pin. They are white or tan-colored when they hatch. After a blood meal, they are reddish-brown.
The immature stage of gradual metamorphosis is called the nymph stage. Many people use the term larva for all immature insects. The plural of larva is larvae.
Like most other insects, immature bedbugs must shed their skin as they grow. Scientists call this process molting. Bedbug nymphs normally molt five times before they are adults. They must get a blood meal each time they molt.
After the first blood meal, a bedbug nymph can survive almost two months without feeding. However, if there is a host available, the nymphs can complete their development in about three weeks.
Between feedings, the bedbugs hide in cracks and crevices. The newly hatched nymphs can fit into very tiny crevices. It is common for bedbugs to hide in the tufts and seams of the mattress where they feed. As the bedbug population grows, they move outward to the bed frame, the headboard, and to the nearby walls and baseboards.
Most people do not feel bedbug bites. Some people become sensitive to the saliva that the bedbugs inject onto their skin. Sometimes people develop itchy welts or swelling near the bite sites. Many people mistake these welts for bites from mosquitoes, spiders, or fleas.
It is easier to recognize bedbugs from other clues that they leave. There are often small blood spots on the sheets or bedding. There are often dark fecal stains in the areas where bedbugs hide. Bedbugs produce a “sweetish” odor that becomes strong when there are a lot of bedbugs in the area. Many people cannot smell it, but sensitive people say it is unpleasant.