Household Pests: Moths

Medically Reviewed by Jabeen Begum, MD on February 08, 2024
11 min read

Moths are a type of flying insect commonly found throughout the U.S. There are wide varieties of moths. Some invade homes, while others don’t. Some are nocturnal and active at night, and others are diurnal, or active during the daytime.

Moths vs. butterflies

Many people may confuse moths for butterflies and vice versa, and they belong to the same animal order, Lepidoptera. Both go through a growth process known as metamorphosis to transition from larva to adult. There are around 160,000 species of moths all over the world, compared with 17,500 species of butterflies.

Some ways to compare moths and butterflies include:

  • Antennae. One way to tell the difference between the two insects is by looking at their antennae. Butterflies have club-shaped antennae with bulbs on each end. Moth antennae are more saw-edged or feathery.
  • Color. Butterflies are known to have more colorful patterns on their wings, while moths are more brown, gray, or neutral-colored. Still, some moths can be colorful, tricking you into thinking they're a butterfly.
  • Size. Butterflies tend to be larger than moths, but moths can vary in size, too.
  • Activity. While moths appear mostly at night, butterflies prefer to fly during the daytime.

What do moths eat? 

People associate moths with fabrics and textiles, as moths typically eat these, but not all of them do. Fabric moths, or clothes moths, like to eat fabrics made from wool and cotton. Many adult moths eat nectar from flowers, rotting fruits, and plant sap. Some moths, such as those that invade pantries, will eat pantry food such as grains and cereals.

Moth life cycle

The moth life cycle includes four stages:

  • Egg. Mother moths will lay eggs on food sources, and they'll hatch within a few days depending on the surrounding temperature.
  • Larva. Larvae, or caterpillars, emerge from eggs and start looking for food to eat so they can continue to grow. For some species, this stage may last 6-8 weeks.
  • Pupa. When ready, larvae will form a silky cocoon or stay unprotected to change or metamorphose into pupae. The pupae look like small sleeping bags. This stage lasts 7-20 days, depending on the temperature.
  • Adult. Finally, the pupa splits open, and the adult moth crawls out and opens its wings to fly. They'll begin mating and lay eggs 3 days after emergence.

How long do moths live?

Many moths have short lives. Some only last a few days after reaching the adult stage and mating. Certain species of moths will live for a few months, or even longer.

Do moths bite?

Adult moths don't bite or sting. There is an exception with the vampire moth species, however. Vampire moths, like mosquitoes, can bite and suck the blood from animals and humans. This behavior has only been observed in male vampire moths.

Pantry moths are common household pests. They are small flying insects that infest or contaminate stored pantry goods such as grain, cereal, flour, and other dry food. They are also known as grain moths or Indian meal moths because they commonly infest powdered Indian corn or cornmeal in America.

Pantry moths are attracted to food sources in your pantry, which they eat, and then they lay eggs. Adult females can lay hundreds of eggs at a time, and the larvae can chew through thin cardboard and plastic bags storing your food. The larvae feed on these food sources, making them inedible. Pantry moths can be difficult to get rid of once they infest the food in your pantry.

Identifying each moth species can be difficult since there are many types of moths. Most moth species look like their butterfly cousin but with duller colors and patterns. Aside from the differences in colors, they also differ in size.

Clothes moth

Some home-invading moths are referred to as clothes moths because they are attracted to fabric. Two species of clothes moths are the webbing clothes moth and the casemaking clothes moth.

  • The webbing clothes moth is more common than the casemaking clothes moth. Webbing clothes moths have golden bodies with red and gold hair on their heads and wings. Their wings are around 1/2-inch wide. They’re known to be weak flyers and aren’t attracted to light sources, so you’ll usually find them hiding inside closets. They tend to chew on and damage fabrics, furs, and feathered items.
  • The casemaking clothes moth is less common but still causes damage to any type of cloth. Like webbing clothes moths, casemaking clothes moths eat and destroy textiles and fabrics. They are similar in appearance to webbing clothes moths, but their wings and hair are of different colors. The casemaking clothes moth’s wings are brown with dark spots, while their head hairs are more light-colored.

You may need to catch and examine these moths with a magnifying glass to identify them.

Pantry moth

Pantry moths are six-legged insects with antennae and wings. They are grayish-brown moths with copper or reddish markings on their outer wings. Their bodies are 1/2 inch (12.7 millimeters) long and oval-shaped. An adult pantry moth’s wingspan, from the tip of one wing to that of the other wing, can range from 5/8 inches (15.87 millimeters) to 3/4 inches (19.05 millimeters).

Pantry moths feed on dry food stored in your pantry such as cereal, grains, flour, beans, seeds, nuts, dried fruits, spices, chocolate, candies, dry pet and bird food, and powdered milk.

A pantry moth’s life cycle lasts 27-305 days. A female pantry moth can lay about 400 eggs after mating. Some types of pantry moths include:

  • Indian meal moth. The Indian meal moth species Plodia interpunctella is the most common pantry moth. These moths are as small as a grain of cooked rice, about 12-13 millimeters long. They have brown wings with a tan stripe and copper-colored tips. You may see Indian meal moth larvae at the junction of a wall and ceiling or in cracks and crevices.
  • Angoumois grain moth. Grain moths of the species Sitotroga cerealella are smaller than Indian meal moths. They are 8.5 millimeters in length. They are yellowish-brown moths with lighter front wings and fringed rear margins.
  • Mediterranean pantry moth. Also  called Mediterranean flour moth (Ephestia kuehniella), this species is pale gray with black zigzag lines on its wings. Beyond flour, this moth can be found in other dry foods or grains. It can't do as much damage as the Indian meal moth, but its webbing may clog machinery used at mills.

White-shouldered house moth

A white-shouldered house moth is white at the top of its wings, closest to its head, with darker tan coloring down the rest of its body. Like pantry moths, these moths can still be a risk to your food. They'll seek out grain and other dry foods, as well as protein-based fibers including wool and leather. They have a wingspan of 15-21 millimeters and can be found anytime during the year in your home.

Brown house moth

The brown house moth originated in Asia but is now found worldwide. Commonly seen in the summer months, these moths have brown spotted wings with a wingspan of 15-26 millimeters. They feed on pantry items as well as clothing and textiles.

Codling moth

The codling moth is small, usually around 1/2 inch in length. Their bodies are usually gray with bands of white, and they have copper-colored wings. Codling moths are mostly nocturnal, so it’s rare to see an active adult codling moth during the day. Their larvae are usually found in fruits such as apples and pears.

Moths aren't picky when it comes to habitat. However, they do require certain conditions to live. For example, there must be enough plants to feed on, especially for caterpillars. Because they love vegetation, you may find moths living in your garden. Many plants that attract butterflies also attract moths.

Pantry moths are found worldwide. They are seen in kitchens, pantries, grocery stores, and other places where food is stored. They infest food and lay their eggs on and around the food source. They also contaminate food products.

Many moths are also attracted to light and may often enter other rooms in your house. New research offers insights into why moths seem to go toward artificial lights. The reason may be that the light source confuses the insect into thinking it's the sky's light, which usually helps them know which way is up. In one recent study, researchers found that insects tilt their backs toward artificial light, and this disorients them while flying, affecting their ability to steer themselves away from the light. They end up stuck circling artificial lights like those around your home.

Signs of moths in your house may vary depending on the moth species.

Moths in pantry

Food- and grain-infesting moths can be frequently seen flying around the house, especially around food sources. They usually fly in a direct and steady manner. If you find tiny moths fluttering in your pantry or resting on shelves, you might have pantry moths. You may also see small wormlike larvae crawling on stored food and the ceilings or walls of your home. It indicates that your house may be infested with pantry moths.

Adult moths are a sign of infested food items in your house. Female moths lay 100 to 400 eggs on or near stored food. The larvae chew through and damage food sources and their packaging, such as plastic bags or thin cardboard. Sealed packages can also get infested.

The larvae feed on the food surface. They spin silky webs, which clump seeds or grains together. They also leave droppings, shed skin, and egg shells on stored food and contaminate it. If you see food covered with droppings or webbings and find holes in plastic bags, you have a pantry moth infestation.

Moths in bathroom

You may find moths hanging around the light fixtures in your bathroom. However, if you spot moths near your sink or tub drain, you may actually be seeing drain flies. Adult drain flies are tiny and dark gray, but some have wings that mimic those of moths. To get rid of drain flies, you can clean the pipes with natural solutions such as baking soda and vinegar, or chemical drain cleaners.

Moths in clothes

For clothes moths, you may notice ruined or damaged fabrics and other textiles, as well as silken tubes and silk cases hiding in clothes.

Moths in carpet

Check your carpets or rugs for bald patches or missing threads. Moths may leave behind eggs, larval casings, or sticky web-like substances.

Pantry moths can be found inside any stored food areas. Female pantry moths lay their eggs on whole grains such as corn, oats, barley, or rice. Packaged food may be contaminated with eggs and may not be detected until much later.

You may unknowingly bring contaminated food into your home. Bringing infested food from the grocery store, pet food, or birdseed can lead to contamination of other stored food in your house. Pantry moths can bore through packaging or enter through small holes in it. The infestation can spread from package to package.

Are moths dangerous? The answer is yes and no. Most moths pose no threat to humans other than simply being annoying pests. However, some moths can be dangerous.

The cinnabar moth is an example of a dangerous moth. These moths have bright red-on-black colors to scare away predators. Their bright colors warn others of their poisonous roots. The cinnabar moth builds up its poison after eating ragwort.

Moth larvae can also be dangerous and cause systemic and skin reactions.

Adult moths don't bite, but if you are allergic to moths, handling them may cause an allergic reaction that you could mistake for bites.

Some people may develop mild allergic reactions to moths, which usually resolve on their own after some time. There's no particular treatment recommendation for moth allergy. However, if you have a stinging reaction to moths, you can apply ice directly to the affected area.

If you develop rashes, you can apply topical steroids or take oral antihistamines. However, these methods may not always be effective. It's important to check with your doctor for a more effective treatment plan.

There are a few steps you can take to prevent moths from coming inside your house or getting rid of them if you already have them. These preventive measures vary depending on the type of moth in your home.

Clothes moths

  • Keep clothes clean. Practicing proper laundry and dry cleaning of clothes is important. Freezing or heating clothing items you can't dry-clean or wash can also help prevent moths from settling on your clothes.
  • Store clothes properly. You can use plastic storage bins, compression storage bags, or sealed garment bags for further protection.
  • Skip mothballs. Mothballs were commonly used in the past, but they're a pesticide, and the fumes they produce could make you sick. Be sure to keep mothballs away from kids and pets since mothballs can also be poisonous if swallowed.
  • Monitor fabrics and textiles regularly. Moving clothes around in your closet and exposing them to light can deter moths.

Pantry moths

For pantry moths, make sure to observe your food items and identify any that have been infested.

  • Remove infested food items. Check for adult moths, larvae (small worms), and webs around all your dry food items, including grains, pasta, and pet food. Any affected food items should be thrown away in an outdoor trash can.
  • Keep it clean. Clear your pantry shelves to carefully clean up any spilled food. Use a vacuum to remove any signs of moths, no matter how small. 
  • Store food properly. Use plastic or glass containers, and make sure they're tightly sealed.

Other methods to get rid of moths

Try these methods to eliminate moths or prevent them from invading your home:

  • Use insecticides. For materials that can't be washed easily, you can use insecticide dust or sprays. You can look for products containing pyrethrins or diatomaceous earth dust.
  • Trap them. Pheromone moth traps or sticky paper traps can help you catch and remove moths around your home, stopping them from reproducing. Keep in mind that this only kills adult moths, while the larvae (that do the most damage) are harder to trap.
  • Fumigate with dry ice. In some cases, you can use dry ice to kill moths on items such as stuffed animals or pillows. One method involves placing the items in a tightly sealed garbage bag with dry ice pellets. Inside the bag, the dry ice will evaporate into carbon dioxide, and after 48 hours, any moths on the fabric will die. Proper ventilation is required to avoid danger from too much carbon dioxide.

If you have a bigger moth infestation problem, you may need to hire a professional pest control company.