These annoying little critters are all types of flies but are best identified by the environment in which they are found.
Gnat is a colloquial term for “small fly”. Because there are several families of flies that can be considered gnats, there aren’t any good characteristics to identify them as a whole group. Each family has its own unique set of characteristics relying on subtle morphology. Generally, gnats do not bite, but they fly around the heads of people and animals, feeding off of mucus released from eyes, ears, and other areas. They are often seen in swarms particularly in moist areas.
If you have gnats in your home, an easy management strategy is to fill a shallow container with a small amount of apple cider vinegar, water, and liquid dish soap. The gnats will be attracted to the cider vinegar and get stuck in the mixture due to the dish soap.
Biting midges (also known as no-see-ums, sand flies, or sand gnats) are tiny bloodsucking flies. They are extremely small (0.08 inch) and are usually gray in color. They are often found near moisture, coastal areas, salt marshes, and in sandy areas, biting in the morning or evening. The best way to avoid them is to use an insect repellent containing DEET or picaridin.
When biting gnats bite, they don’t do it the way a mosquito does. Mosquitos have needle-like mouth parts that they use to pierce skin, while ghats use scissor-like jaws to cut open the skin. Their saliva can cause an allergic reaction, which for most people is usually mild. They can’t bite through fabric, so they only affect exposed skin.
If you have bites, clean the area as quickly as possible with warm water and antibacterial soap to remove any remaining saliva/toxins. Reaction to bites generally consists of localized stinging or burning sensations with defined red areas surrounding bite sites. While discomfort usually lasts for minutes to hours, individuals who are hypersensitive to bites may itch for two to three days. The fastest way to heal a no-see-um bite is to immediately reduce inflammation and stop the itch-scratch cycle using ice or a cold compress, oral antihistamines (like Zyrtec or Benadryl), and hydrocortisone cream.
Fruit flies are brownish or orange with round lower bodies. They fly slowly, usually just hovering over their food. They eat the yeast found on rotting produce or decaying plants and animals. Keeping your home free of over-ripe/spoiled fruit, potatoes, onions, or any spilled fermented goods like beer, liquor, or wine, will prevent the attraction of fruit flies. Fruit flies also may breed in drains, garbage disposals, empty bottles and cans, trash containers, mops, and cleaning rags. A good approach to getting rid of fruit flies in your home is to construct a trap by placing a paper funnel (rolled from a sheet of notebook paper) into a jar which is then baited with a few ounces of cider vinegar and a piece of fruit such as a slice of banana. Place the jar trap(s) wherever fruit flies are seen. This simple but effective trap will soon catch any remaining adult flies which can then be killed or released outdoors.
NOTES:
Ask an Entomologist
Wikipedia
Ask IFAS (University of Florida)
Mosquito Squad
KOA.com
