Bot flies are mainly found in the Americas, especially in regions where their animal hosts (like rodents, rabbits, livestock, and deer) are common. Some species are limited to tropical Central and South America, while others occur widely across temperate North America, including the United States and Canada.

General geographic range

  • Many bot fly species live in the Nearctic region, covering most of North America from Canada down into central Mexico.
  • Human bot flies (Dermatobia hominis) are native from Mexico down through Central America into Paraguay and northeastern Argentina.
  • Rodent and rabbit bot flies (genus Cuterebra) occur across large parts of the eastern and central United States and into several Canadian provinces.

Typical habitats

  • Bot flies tend to be found where their hosts are abundant, such as forests and brushy areas that support rodents and rabbits, or pastures and stables that house horses and livestock.
  • Adults are often near animal burrows, on forest edges, or around barns and paddocks, while larvae live in or on the tissues of their hosts until they mature and drop to the soil to pupate.

Common hosts and where you might encounter them

  • Different species specialize on different hosts, including mice, rabbits, deer, horses, cattle, sheep, dogs, and other warm‑blooded animals.
  • People most often encounter bot flies indirectly—on pets or livestock in North America, or as travel-related human infestations after visiting tropical areas where the human bot fly is endemic.

TL;DR: Bot flies are found across much of North America and throughout parts of Central and South America, especially in habitats where their mammal hosts live, from forests and fields to farms and stables.

Information gathered from public forums or data available on the internet and portrayed here.