Lipoptena cervi

Lipoptena cervi, the deer ked or deer fly, is a species of biting fly in the family of louse flies, Hippoboscidae. These flies are commonly encountered in temperate areas of Europe, Siberia, and northern China. They have been introduced to North America. They are parasites of elk, deer, and other deer family members, burrowing through the fur and sucking the blood of the host animals. Adults are only 5–7 mm (0.20–0.28 in) in length and brownish in colour. Their bodies are flat and elastic, making their removal difficult. L. cervi is a poor flier and can only fly for short distances. Once the insect reaches its target, it sheds its wings and starts burrowing through the fur.