As the weather heats up, flies can be a particular problem for horses. Horseflies can be particularly nasty, they will bite through the skin of your horse and gorge themselves on their blood. They may also lay their eggs around the area of your horse’s eyes, nose and mouth which can lead to nasty irritations that can really upset your horse. It is possible that your horse may suffer an allergic reaction to being bitten by a fly, in much the same way as humans can. This might result in an area of irritated skin or may even cause lumps on the skin. There are things that you can do in order to help reduce exposure to flies such as stabling as flies prefer bright places however especially in the very hot weather this can be unpleasant for your horse. A repellent can be used to help repel the flies and should prevent the flies from landing on and biting your horse.