What are horse and deer flies?
Horse and deer flies are large flies that bite people, livestock and wildlife. Bites can be very painful but these flies do not transmit disease in humans. Horse flies are more likely to attack livestock, including horses, where their persistent biting can adversely affect animal health. People are generally more bothered by deer flies but horse flies will also attack us, the difference may be related to body size. Both flies are active during daylight hours.
