Horseflies are large, biting insects belonging to the family Tabanidae. They are known for their painful bites, which they use to feed on the blood of mammals, including horses and humans. Horseflies are typically found near water sources and are most active during warm months. These insects have large, compound eyes and strong wings, allowing them to fly quickly. Horseflies are often gray or black, with some species displaying colorful patterns. They play a role in the ecosystem as both pests and pollinators, although their bites can be quite irritating to both animals and people.