Different House Fly Species
Several house fly species infest American homes. Infestations begin when flies locate decaying material within which to lay their eggs. Because house flies lay large batches of eggs and have a rapid reproduction cycle, a few errant flies can quickly become a problem.
The common house fly (Musca domestica) is a gray-black fly measuring 5 to 8 mm in length. These flies have two wings, a highly developed mouth organ and very large, faceted eyes. The average life span of the common house fly is approximately one month.
The lesser house fly (Fannia canicularis) is smaller than the common house fly. They are about two-thirds the size.