Gnats come in a variety of species. Not all of them are harmful to humans. However, some gnats spread disease and endanger the health and well-being of people and livestock. Learn more about what gnats look like and the impact they have on your home and the world around you.
Gnats are flying pests. They stay close to where they lay their eggs. To get rid of gnats, it’s important to understand what kind you are dealing with. Gnats are in the fly family, but not all flies are gnats.
Most gnats prefer moist areas with organic material. Some species like the soil used for houseplants and others prefer decomposing food in your garbage disposal. Wetness and unsanitary habits draw them to your home. Clearing drains and cleaning up the areas where you find them helps to eradicate gnat infestations.
Let’s take a look a the different kinds of gnats.
Table of Contents
- Fungus or Houseplant Gnats
- Drain Flies
- Sand Flies
- Unique-headed Bug
- Buffalo Gnats
- Gall Gnats
- Eye Gnats
Fungus or Houseplant Gnats
There are more than 1,000 species of black gnats. The most common is the fungus gnat. Fungus gnats, also known as winter gnats, are 1/16 to 1/8 of an inch in size. Adults are grayish-black and have long see-through or gray wings with visible veins, and their legs are very long. These tiny insects eat the fungi and roots of plants.
Nearly invisible, fungus gnat eggs are smooth, oval and shiny white. During the larval stage, they are white and thread-like, with no legs. Pupae form cocoons in the soil.
These insects live up to a month and reproduce in homes with warm interiors and climates. The females lay around 300 eggs on most soils, and fly around lamps and windows due to their attraction to light. Eggs take three days to hatch.
At rest, drain flies fold their wings over their bodies and they may grow up to 5 mm long. In the larval stage, they are 4-10mm long with no eyes or legs. On one end, the larvae have a dark breathing tub and there is a dark stripe on the dorsal area.
Drain flies hang out in drains or sewers and can block pipes by collecting the filth they live in. You may see them if you have a plumbing issue. They reproduce in drains and sewers or anywhere there’s decaying organic matter. The larvae take three days to mature.
These pests come in large numbers. Although they spread bacteria, they don’t typically cause diseases in humans.
Biting midges live in swampy areas. They bite and extract blood from humans and other animals. Non-biting midges, or chironomids, resemble mosquitoes, and the adults are gray and less than 1/8 of an inch in length. They have segmented antennae and females have a long proboscis to extract blood. Full-grown, they are about the size of the lettering on a dime.
Midges live in aquatic habitats such as fast-flowing streams and deep lakes. In the larval stage, they can suspend development in the fall and winter. Adult midges can feed on nectar and sugary substances and die within five days. In warm weather, from egg to adult, the full life cycle lasts less than three weeks.
Named for their sandy color, sand gnats grow from 1/8 to 1/10 of an inch. They have thick hair on their body, and legs and have big black eyes. Females feed on blood before laying their eggs, and both males and females eat sugary nutrients from plant nectar. Some species feed off reptiles and mammals.
They live in humid environments in a dry area, which protects their eggs. The entire lifecycle is 20-40 days, with 1-2 weeks needed for the eggs to hatch into the larval stage. Pupae develop into adults within 10 days.
Many people get bumpy red rashes around the bite areas, and some victims get a fever. Viral infections passed on by sandflies include Chagres Virus and Punta Toro Virus.
Also called gnat bugs, unique-headed bugs include 130 species. These small insects grow to 4 mm long. Their elongated head is constricted in places, inspiring the name. You can find them under leaf litter, bar and rocks, and they sometimes swarm in sunny patches of woodlands, similar to midges.
These bugs have unusual membranous membranes devoid of a thick basal area. Their probosci and antennae both have four joints, while the front legs are designed to grasp prey. Not much is known about these unique insects, but most gnats have lifecycles of less than four weeks.
Humpbacked buffalo gnats, also known as turkey gnats or black flies, grow to 1/8 of an inch long. They emerge in late spring or early summer. While the males feed only on nectar, the females swarm animals, including birds and people, and suck their blood. Buffalo gnats are drawn to dark objects on the move, sweat and carbon dioxide.
They are tan, green or gray and breed in fast-moving rivers and streams. Luckily for livestock and people, buffalo gnats live just 2-3 weeks and disappear in the hot summer months.
Black flies are a nuisance to people attempting to work or play outside. These gnats bite around the neck and head and are so aggressive they can kill animals through nuisance effective. For example, chickens may die of suffocation when the insects clog their respiratory tract. Wild birds can die of toxic shock due to the saliva left behind by black fly feeding.
Gall Gnats inject their larvae into plant sap, where they receive nourishment but cause plants to grow abnormally. They cause infections and interfere with plant growth. These minute insects are small delicate flies that look like mosquitoes. However, they don’t bite. Its multi-jointed antennae have whorls of hair. The wings have one main cross-vein with multiple longitudinal veins. The hair on the body and wings rubs off easily.
The eggs hatch into flattened maggots with tapered ends. They are often brightly colored with red or yellow shades. The pupa is often enclosed in a silk cocoon. Adult females eat pus, animal sweat, sebaceous secretions and blood to obtain proteins for egg production. Females produce up to 400 eggs in 3 days.
Reputedly brought over from Europe by Hessian soldiers, this species lives in wheat during its larval stage. Every year, Hessian flies damage millions of dollars worth of wheat crops.
These gnats feed on the seed then emerge from closed florets once they are fully grown. They wriggle out of the plant until they fall to the ground and form ovular, tough cocoons. Particles of earth stick to the cocoon, effectively camouflaging it. The pale orange pupa emerges in 10 days as a Hessian fly adult.
As an example of its proliferation, there are two to three generations produced in the New York and D.C. areas. Hessian flies also breed in white clover. It’s often so numerous it destroys the crop across the United States.
Other names for eye gnats include grass flies. These tiny bugs congregate near the nose, mouth and eyes of human and animal victims. They are attracted to secretions from these cavities. Because of their habits, they often transmit pink eye, They thrive in areas of loose, sandy soil.
Eye gnats’ life cycles vary based on the temperature, food and moisture available. In general, they live about 28 days. Adult females eat blood, animal sweat, secretions and pus, or blood to build up a protein reserve for the pupa and larval stage. Females lay up to 400 eggs in 2-3 days.
To deal with a gnat infestation, first, identify the type of gnat in your home. Then figure out a way to get rid of them permanently. This handy guide can help you learn exactly what you’re dealing with.
How long do gnats live?
A gnat is not a specific species of insects. Instead, it is a family that includes many species of small, flying insects. While these species each have their unique physical characteristics and other identifying features, you will find that most of these species share a few common traits. The lifespan of an adult gnat, for example, ranges between seven to 14 days. Their overall life cycle, however, is approximately a month.
Where do gnats come from?
All types of gnats hatch from eggs laid by a female. A female may lay several hundred eggs or more during her lifetime. Generally, gnats lay their eggs near organic matter in a wet environment. When the eggs hatch, the larvae remain in the water for several weeks as they mature through the pupal stage.
When they reach the pupal stage and transition to the adult stage, they will move toward the surface of the water and grow wings. During their adult stage, they live close to the water and organic materials. The females may lay eggs several times before dying.
What attracts gnats?
Gnats are commonly attracted to food sources and to areas that are ideal for reproduction. All types of gnats need moisture and organic materials, but the types of materials that they are attracted to varies. For example, some gnats consume decaying organic matter that is found in all types of moist soil.
If you have these types of gnats in your home, they are likely coming from potted plants that have excessively moist soil. Other types of gnats consume the organic material that may be in your wastewater system or garbage cans. For example, they may live in your garbage disposal or drains. They may also be found around fruit bowls that hold aging fruit.
What do gnats eat?
All types of gnats eat organic material, but their specific food sources vary by species. While some types of gnats eat fungus, others consume spoiled fruits and vegetables indoors or on farms. They can also feed on manure as well as organic waste material in pipes and drains, in waste bins, and in other similar areas. Biting gnats feed on the blood of humans and other mammals.
Are gnats harmful or dangerous to people?
At various stages of the gnat life cycle, gnats can be harmful to plants. However, this is rare. For example, gnats that live around over-watered soil can damage the roots of plants if the insects are present in large numbers. On the other hand, non-biting gnats are not harmful to people regardless of how many gnats are circulating around you, but they can be irritating.
This is particularly true if they are swarming while you are trying to relax outdoors. Biting gnats, on the other hand, consume blood and will cause itchy whelps on the skin. Unlike mosquitoes, gnats actually slice a small area of the skin before sucking out blood. Because of this, you may discover that a gnat bite is slightly more painful than a mosquito bite. Most gnats do not spread diseases to humans.
Are gnats attracted to light?
During the adult stage of their life cycle, gnats are attracted to light sources. For this reason, you may see them flocking around illuminated lamps and other light sources. If they are problematic in the evening, such as if you are sitting on your patio, you can turn off the light to encourage them to disperse.
Are gnats harmful to plants?
Many species of gnats are found around vegetation and wet soil, but most of these gnats do not feed on live plants. Instead, they feed on organic matter in the soil. This may include rotting sections of plant roots. However, gnats may begin to feed on living roots when they are present in large numbers and require more food than what is present in this soil. If this happens, the plants may begin to wilt or show signs of stress.
Are gnats the same as mosquitoes?
A gnat is a large family of insects that includes species like non-biting gnats, flies, and mosquitoes. Because of this, mosquitoes are a type of gnat, but not all gnats are mosquitoes.
Can gnats bite?
While gnats can and do bite humans and other mammals, most of them do not. Most gnats feed on decaying organic materials, such as dead plant roots and leaves, rotting fruit, and other vegetative debris. The few gnat species that feed on mammalian blood will bite in order to access the blood.
Which animals eat gnats?
Gnats are understandably bothersome to have inside your home as well as on your patio or in the yard. In an outside environment, gnats are a great food source for a wide range of bugs and animals. This includes various species of birds, bats, ladybugs, and more.
While these and other animals and critters eat adult gnats, nematodes will feast on larvae. Because of this, introducing nematodes into your garden or yard can prevent an infestation or may slowly stop an active infestation by interrupting the life cycle.