Gnats are a common term for various small, winged insects. While the label “gnat” is broadly applied, only certain species bite humans. Understanding which types bite and their habits, particularly at night, can help prevent uncomfortable encounters.
Identifying Biting Gnats
Many small, flying insects are called “gnats,” but only specific types bite humans. Female biting species require a blood meal to produce eggs. Common culprits include biting midges, black flies, and sand flies, which can be active at night or during dusk and dawn.
Biting midges, also known as “no-see-ums” due to their minuscule size (1-3mm), are often the primary cause of nighttime bites. While most active around dawn and dusk, these insects can continue to bite throughout the night, especially under calm conditions. They are drawn to light and readily enter homes to feed, making them a nuisance indoors.
Black flies, sometimes called buffalo gnats, are typically active during the day, particularly in late spring and early summer. However, some species can bite near dawn and dusk, and their activity may extend into the night under certain conditions. These flies are about 1/5 to 1/4 inch long and have a characteristic humpbacked appearance.
Sand flies, which are larger than midges but smaller than mosquitoes (about 3mm), are also known for their painful bites. Most species that bite humans feed during the evening and throughout the night. They are weak fliers, and windy conditions tend to reduce their biting activity. In contrast, common household gnats like fungus gnats and fruit flies do not bite humans, lacking the necessary mouthparts.
Gnat Bite Symptoms and Reactions
Bites from these tiny insects often cause noticeable reactions, though severity varies among individuals. A bite typically results in a small, red welt that can be intensely itchy and painful. Redness and swelling around the bite site are common.
Some individuals may experience a burning sensation immediately following a bite. Bites can develop into blisters or become weepy, persisting for days or weeks. Scratching bites can lead to secondary bacterial infections.
Most reactions are localized, but sensitive individuals may experience more severe responses, including significant swelling or persistent discomfort. Medical attention may be necessary if signs of infection, such as pus, increased warmth, spreading redness, or fever, develop. Severe allergic reactions, though rare, require immediate medical attention.
Strategies for Bite Prevention
Preventing bites from nocturnal gnats involves a combination of personal protection and environmental control. Using insect repellents containing active ingredients such as DEET, picaridin, or oil of lemon eucalyptus (OLE) is effective. When applied to exposed skin, these repellents create a barrier that deters biting insects.
Wearing appropriate clothing can also provide a physical barrier against bites. Long-sleeved shirts, long pants, and closed-toe shoes help cover exposed skin, especially if you are outdoors during peak activity times. Tucking pants into socks can further minimize access for these small insects. Light-colored clothing may also be less attractive to some biting gnats.
Securing your living space by installing fine mesh screens on windows and doors can prevent insects from entering your home. Eliminating standing water sources near your residence is important, as many biting insects breed in moist environments.
Utilizing fans or air conditioning can also help deter biting insects. Moving air from fans makes it difficult for weak-flying gnats to navigate and disperses the carbon dioxide and body odors that attract them. Air conditioning can create a cooler, less humid indoor environment, which is less appealing to these insects.