Ynghylch

The Twin-lobed deer-fly is a species of horse-fly and, as such, the females have sharp, biting mouthparts and feed on the blood of large mammals, such as cows and ponies, but will also happily drink the blood of humans. The males lack these mouthparts, so feed on nectar. Females wait in shady areas for their prey to pass-by, locating it by sight with their large compound eyes. The eggs are laid on stones and plants, or in mud, close to water. When the larvae hatch they fall on to the damp earth where predate other invertebrates. This biting insect can be a real nuisance during the summer, especially in hot, thundery weather.