Black flies include several species of small, dark flies known by various common names, including buffalo gnats, sand flies, punkies and no-see-ums. These biting pests can measure 1/20 to 1/3 inch in length. Viewed in profile, their hump-like thorax looks like the hump on a buffalo's back. Depending on the species and your local weather conditions, these pests can produce several generations per year.

Black fly larvae mature in water, like mosquito larvae. These pests prefer cool, clean streams and rivers rather than the stagnant, standing water that mosquitoes target. But black flies can develop in backyard water features, too. The legless, wormlike larvae look similar to mosquito larvae, but their bulbous bottoms draw comparisons to bowling


The first signs of a black fly problem are usually the painful bites suffered by people, pets, birds, and other wildlife. Some types of nuisance black flies buzz into ears, eyes, noses, and mouths. Other types bite and feed on blood, like extremely aggressive mosquitoes, to get a meal before laying eggs. Adult black flies often appear in swarms.

Rather than piercing skin, black fly mouthparts slash like tiny blades. The painful, bleeding bites swell, itch and throb for days or even weeks. Humans may get headaches, fever, and nausea when bit. Small animals and children are especially vulnerable to severe reactions.


Black flies are known to travel several miles, so waterfront property isn't required for their visits. Crowded gardens with poor air circulation provide cover as these pests mate, bite, and feed. When known black fly problems exist, treat early in the year to help prevent bites. Treat again at the earliest sign of new black flies.

Amdro brand offers two highly effective options to protect your family, including your pets, against black fly bites. These products even treat your home's foundation up to a height of 3 feet:

  • Amdro Quick Kill Outdoor Insect Killer Ready to Spray works in minutes to kill black flies. Then it keeps protecting against black flies for up to three months. Just attach the container to a standard garden hose to spray lawns, trees, shrubs and flower gardens. The container measures and mixes automatically as you spray.
  • Amdro Quick Kill Outdoor Insect Killer Concentrate, with a convenient measuring cap, kills black flies by contact and keeps protecting your lawn and landscape against these pests for up to three months. Dilute the product according to label instructions in a regular pump-style garden sprayer. Then spray your lawn and landscape plants thoroughly.


Black flies are most active right after sunrise and right before sunset. For maximum results, treat during those active times.

Always read product labels and follow the instructions carefully.

Is this not your insect?