There are over 4,000 species of biting midges, ranging in size from 1-3mm in length. The distribution of midges in the genus Culicoides is world-wide. They are found in marshy habitats, as well as mountainous regions, depending upon species. One of the areas most renowned for human feeding midges (typically Culicoides impuncatus) is the Highlands of Scotland, where midges can cause discomfort to tourists and disruption to outdoor industry, including agriculture and forestry.
Both males and females feed on nectar, but like many insects in this section, the females need blood for their eggs to mature. They only live for a few weeks under natural conditions but can lay up to 100 eggs per blood meal, depending on the species.
Biting midges are a nuisance to anyone who enjoys being outdoors and their bites are irritating and painful. They are most active in the early morning and evening, but can remain active all day when it is cloudy with little wind. In Central and South America, western and central Africa, and some Caribbean islands, biting midges are more than just a nuisance. They are the vectors of filarial worms which can cause skin infections and lesions. Biting midges are often incorrectly referred to as Sand Flies.