Blackflies are small black flies with a humped appearance that are pests of man and animal.
Female blackflies, requiring blood to lay eggs, bite humans and animals, while the male blackfly feeds on plant material. Blackflies are a nuisance and cause itching bites. When present in large numbers, they fly into the ears, eyes, nose and mouth. They are attracted to animals by the carbon dioxide and moisture present in exhaled breath, by sweat and by dark colors. In some cases they can even cause the death of animals by suffocation and loss of blood.