Fruit Flies vs. Fungus Gnats: Whats the Difference?

This page is a general guide that explains the differences between fruit flies and fungus gnats. To remove fruit flies and fungus gnats in your home then follow the links in this easy to use DIY guide and use the recommended products for complete control.

Often, homeowners assume tiny flying insects around their kitchen and home are either fruit flies or fungus gnats since they are both common indoor pests. While fruit flies are commonly mistaken for fungus gnats they are their own types of pest and each have their own separate issues.

Fungus gnats are primarily a problem for indoor house plants and other potted plants as the larvae will feed on the plants roots, limiting its ability to take up nutrients and stunt its growth. While you may not have many potted plants in your house to deem this an issue the fungus gnat can become a nuisance due to large population numbers and annoying hovering.

Much the like fungus gnat, fruit flies quickly overwhelm kitchens or other indoor areas of your house with their fast-reproducing rates. Other dangers associated with this pest is any physical contact with contaminated food results in skin irritations or allergies for some homeowners. Regardless, learning the physical and habitat differences between fruit flies and fungus gnats in this article can better prepare any do-it-yourselfer.

Is It A Fruit Fly or Fungus Gnat

Before you can proceed with a treatment approach, you will first need to know what fruit flies and fungus gnats look like. At a quick glance they may look the same, but fruit fly and fungus gnats are not the same pests: by knowing the physical differences you can avoid using the wrong products.

For a physical reference, take a look at the image above. On the left is a fruit fly and on the right is a fungus gnat.

Size

Fruit flies and fungus gnats both measure about 1/8th of an inch in length.

Color and Body

Fruit flies are tan in color and have the round body shape of a house fly just smaller.

Fungus Gnat have a longer and more narrow body shape than fruit fruit flies and they also have large, gangly legs that resemble that of a mosquito. These pests range from dark brown to black in coloration.

Eyes

Fruit flies are easily seperated from fungus gnats by their large red eyes whereas fungus gnats are small, and compound. 

How to Know If You Have Fruit Flies or Fungus Gnats

After you have compared the physical differences in these pests, you may be wondering how fruit flies or fungus gnats got into your home? Both of these pests can live outdoors, but they often travel into your home through various methods.

When fruit flies are inside they stay near warm and wet organic areas such as the slime in sink drains, garbage disposals, fruit or vegetables sitting out on kitchen counter top or in bowls, and around rotting fruit in trashcans as it creates an ideal site for breeding and food. Fruit flies can find their way into your home through cracks and crevices around windows and doors, or, may simply be a previous infestation from past egg laying activities on food brought from the store or garden.

Fungus gnats are mainly found outdoors as they depend on a moist environment with decaying matter like fungi to feed on, which is often located within soil. Damp soil in outdoor gardens and indoor potted plants are often hot activity spots for fungus gnats. Usually fungus gnats come into your home by traveling through open doors, cracks and crevices around the structure, or could be pests hatched from eggs laid in potted plants that were brought from the outside.

Do Fruit Flies or Fungus Gnats Bite

Though fruit flies and fungus gnats are flies, they do not bite people or animals. These pesky non-biting flies do not have the necessary mouthparts to bite or penetrate skin.

Fruit flies will pierce fruit and vegetables by releasing catabolic fluid that helps break down their food then use their mouthparts to suck it up or to insert its eggs. While fruit flies won't bite people they can cause allergic reactions such as itchy, irritated red bumps on your skin causing homeowners to think they have been bitten.

Due to their name, fungus gnats are often lumped in with other gnat pests such as no-see-ums, which can cause tiny, red bumps that are itchy and irritating. However, as mentioned earlier the fungus gnat is a type of small fly and not a gnat at all.

Key Takeaways

How to Get Rid of Fruit Flies

• To get rid of fruit flies you will first need to sanitize your home by getting rid of all rotten or uneaten fruit and vegetables, wiping off counter tops with a rag soaked in warm water, then sealing all exposed foods in a plastic container. Treat other breeding and food source buildup in drains, sinks, and garbage disposals with Forid Drain Gel Cleaner. Once all food sources have been removed, set up a fruit fly trap like Natural Catch Fruit Fly Traps. Spray any fruit flies in sight with Pyrid Insecticide Aerosol.

How to Get Rid of Fungus Gnats

• To get rid of fungus gnats, address any moisture buildup in and around your home and potted plant. To avoid excessive moisture, simply spray indoor potted plants with a spray bottle and let enough days pass for the soil to dry. Apply fly traps like Musca-Stik around indoor potted plants, then taking indoor potted plants outside and treating it with Supreme IT. Allow enough time for the plant to dry before bringing it back in. Lastly, directly spray Pyrid Insecticide Aerosol on fungus gnats that you may see traveling in your home.

Do Fruit Flies Live in Potted Soil

• Fruit flies do not live in potted soil, but are found near them due to their need to feed on rotten organic debris like fungi and any fallen fruit or vegetables.