A fly mask or fly cap is a mask used on horses to cover the eyes, jaw, and sometimes the ears and muzzle to protect from flies. The mask is semi-transparent and made from a mesh allowing the horse to see and hear while wearing it. The mask may also provide some protection from UV-light and some are treated with insect repellent.^[1] Fly and mosquito protection is an important part of overall horse care, as biting insects are both a source of irritation and also may transmit disease.