What Are Carpet Beetles? (And What to Do About Them)

No homeowner wants to hear that their home has been infested with any kind of pest, and it’s usually worse when you don’t even know much about the pest in question. Carpet beetles aren’t a well-known pest for most homeowners, and you may be wondering just what they do, and why they can be a problem.

In this article, we’ll cover everything you need to know about what carpet beetles are, and what they do. We’ll also tell you how to identify a carpet beetle infestation, and what you can do to prevent one.

What Are Carpet Beetles?

Carpet beetles are a group of beetles that lay their eggs in fibrous materials like carpets. When they hatch, the larvae then feed on the material they hatched in. They may even infest your bed, like bedbugs, to feed on the dead skin cells you leave behind. Fortunately, they won’t bite like bedbugs do.

They can cause extensive damage to your carpet, as the larvae will eat the fibers of your carpet. Carpet isn’t the only thing they eat, either, and carpet beetles may also infest your pantry and your closet. Some species eat grains and dead insects in addition to fabrics and carpet fibers, which means an infestation may not be limited to your carpet.

These beetles are all very small, which can make them very difficult to see. Their larvae are also very small, so it can be difficult to even know when you have an infestation of carpet beetles. Only the larvae will infest your home- the adults will only enter your home to find a good place to lay their eggs.

Carpet Beetles in the US

There are many different carpet beetle species in the United States, but three are especially common. The first is the black carpet beetle (Attagenus unicolor). This species will feed on fibrous materials, like fabric and carpets, as well as things like grain and other stored foods.

Adult black carpet beetles are bullet shaped and dark brown to black in color, with brown antennae and legs. Their larvae are about half an inch long, carrot-shaped, and covered in golden brown hair.

The varied carpet beetle (Anthrenus verbasci) feeds on dead insects in addition to fibers and fabric. Adults grow to about 3mm long and have white, brown, and yellow spots which gives them a mottled appearance. Their larvae are 5mm long and have tufts of bristly hair.

varied carpet beetle | image by Bert Cash via Flickr | CC BY 2.0

The common carpet beetle (Anthrenus scrophulariae), sometimes called the buffalo carpet beetle, likes to eat things made with animal byproducts. This means if you have a carpet made of synthetic fibers it’s probably safe from this species. Adults are black and white with a single red-orange line running down the middle of their backs. Larvae are reddish brown and covered in hairs.


How to tell if you have carpet beetles

Since they can cause a lot of damage, and since nobody really likes the thought of their carpet being full of beetles and beetle larvae, you’ll want to know how to detect these tiny pests. It can be tough, since carpet beetles are small and like to hide in dark, secluded places.

Unfortunately, it’s just about impossible to detect a carpet beetle infestation before they’ve begun to cause damage. You may be able to spot the shed skins of larvae, which are dry and flaky, but it will likely be difficult to identify and most people don’t recognize these skins for what they are.

The most reliable way to detect a carpet beetle infestation is to spot the damage they leave behind. They eat fibrous materials and fabrics, so portions of your carpet, and even your clothes or curtains will be damaged.

Carpet beetles focus on eating one portion of fabric at a time, so the holes they leave behind will be fairly large but isolated. This helps you to be sure you’ve got carpet beetles and not moths.

How you get carpet beetles

Carpet beetle larvae are what’s eating your carpet; if you’re seeing adults, they’re likely just passing through. The adults will come into your home to lay their eggs, and then leave. Only the larvae stay behind.

The adult beetles actually feed on flower nectar, and are likely drawn to the flowers in your yard. As they fly around looking for flowers to feed on, they may stray into your home on accident. The beetles are more active in warm weather, which means infestations typically begin in the summer.

They like to lay their eggs in secluded, dark places, and so the infestations often begin in attics or basements. In addition, the adult beetles are so small they usually go unnoticed. Many infestations probably begin when humans inadvertently carry a carpet beetle into their home on a piece of fabric.

Once inside, the adult females will look for good food sources for their larvae before they lay their eggs. If they find one, you’ll soon have an infestation on your hands.

How to prevent carpet beetle infestations

While carpet beetles are perfectly capable of chewing through whole fabric, they really prefer loose, easily consumed sources of food. Damaged or torn fabric is therefore much more desirable to them than whole, undamaged fabric. An old, damaged rug is a carpet beetle magnet.

Lint, hairballs, dust, dead insects, and damaged furniture are all favorite food sources for carpet beetles, in addition to fabrics and rugs. Regular sweeping and vacuuming can go a long way to preventing an infestation.

It’s also a good idea to get rid of old clothes, sheets, and rugs. Wash sheets regularly and don’t keep too many extra sets of them. Store any fabric in airtight containers to prevent the beetles from getting in.

Essentially, you’re minimizing or eliminating the food sources for their larvae. If the adult beetles can’t find a rich, consistent food source for the larvae, they won’t lay their eggs there. So, as long as you can minimize the food for them, you can avoid a carpet beetle infestation.