That's why they will bug you more in late afternoon as the sun sinks and on overcast days. They also tend to lurk in shady areas. Williams, who lives fairly near a marsh, says one of his tricks is to tackle his spring gardening while the weather remains too cool for the gnats. The smallest of the biting flies, these gnats breed in salt and fresh water habitats around the world and are found mostly along the seashores and river shores plentiful in the Lowcountry. They're found in practically any kind of mud near wetlands.
Adults deposit eggs on mud or sand, and about a week later larvae emerge.
They're found in mud, saltmarshes and intertidal sand. Larvae consume decaying matter in wet areas. Adults chow on liquids, including blood from humans and other mammals, reptiles and other insects. They also like plant juices, according to the National Integrated Pest Management Network. Yet, because gnats breed in marshes that flood with every high tide, they are tougher to control than mosquitoes, which hatch on very high lunar tide or after heavy rainfall, Hyatt says.