The Notch-horned Cleg-fly is a common species of horse-fly, which lives in long grassland and damp woodland habitats. The females have sharp biting mouth parts and feed on the blood of large mammals, usually cows and horses, but will happily drink the blood of humans too. The males lack these mouth parts, and so, feed on nectar. Females wait in shady areas for their prey to pass-by, locating it by sight with their large compound eyes. This biting insect can be a real nuisance during the summer, especially in hot, thundery weather.