Horn fly adults typically occur on cattle, but may infest other livestock such as horses. Unlike stable flies, adults will not bite man. They are cylindrical and taper anteriorly. Puparia are dull reddish brown and 3 - 4 mm long. The respiratory horns found along the posterior border of the 4th segment in most other muscid species are minute and difficult to see.
Horn flies occur in open pastures and rangeland.
Both sexes bite and may feed up to 40 times per day. Females require blood meals for egg production and can lay several hundred eggs during their lifespan. They leave the host briefly to lay eggs on fresh undisturbed cattle manure. Mature larvae move below the pats into the soil to pupariate and emerge as adults 1 to 2 weeks later. The entire life cycle from egg to adult is completed within 2 to 4 weeks, and 3 to 4 generations may occur throughout the summer.