There are five species of carpet beetles that are commonly found in homes in the United States. They develop through a complete metamorphosis. This means that the beetle's body undergoes a complete change as it develops from an egg to an adult beetle.
There are three immature stages, egg, larva, and pupa, before the beetle becomes an adult. Each species of carpet beetle requires a different time for its life cycle. The time will also vary according to the climate and the amount of food that is available.
The female beetle deposits eggs near the food that the immature larvae will need. The larvae need a chemical called keratin for their development. It is found in fur, feathers, and hair. The female beetle deposits the eggs in corners or in crevices where lint and hair have accumulated.
The eggs are tiny and white. Because of their small size and the obscure location, the eggs are seldom noticed. Depending on the temperature, the eggs hatch in about two weeks.
Immature carpet beetles are called larvae. They are about 0.5″ long. Depending on the species, they can be tan, brown, or almost black. Carpet beetle larvae have many hairs on their bodies. These hairs give them a bristly appearance.
When they first hatch, the larvae stay hidden in dark crevices. After a few weeks, the larvae begin to wander around searching for food. They shed their skins 15 or 20 times as they grow and develop. It is common to find the cast off larval skins, especially in the areas where they are eating.
Depending on the climate and the amount of food that is available, the larva stage can last for more than a year. When the larva is fully developed, it moves into a dark crevice. It remains still while its body changes from a larva into an adult beetle. This changing process is called the pupa stage of the beetle's life. The pupa stage lasts about two weeks.
When the pupa stage is finished, the beetle emerges as an adult. In the adult stage, the beetle mates and produces eggs. Some species of carpet beetles require a meal of pollen in order to produce eggs. It is common to find adult carpet beetles on flowering plants like crepe myrtle.
Inspect the home carefully and remove any bird or rodent nests. Screens on windows and vents can help prevent adult carpet beetles from moving indoors. If the home has a brick exterior, the weep holes can also be an insect entryway. Small squares of plastic screen can be inserted into the weep holes. The screen will keep insects out but allow air to circulate.
A vacuum cleaner can help remove carpet beetle eggs and pupae. The vacuum will also pick up some of the larval skins. Eliminating the food that the larvae eat will be an important part of carpet beetle control.
Have woolens cleaned and store them securely. Wash or clean other fabric items. In the kitchen, discard any infested food packages and store food in sealed containers. Vacuum pantry and cabinet shelves. If larvae have attacked animal trophies or valuable antiques, it may be necessary to consult a specialist before trying to clean the item.