Extension Logo
Extension Logo
University of Minnesota Extension

Common flies around horses and how to control them

Quick facts

  • You can best control filth flies by managing moist organic debris sources:

    • Manure and bedding

    • Rotten feed

    • Mud

  • Traps, stingless parasitic wasps and insecticides for filth flies are most effective when combined with debris management.

  • Managing water sources and providing your horse deep shade or housing can best protect them from aquatic biting flies.

  • Work with a veterinarian to have your horse vaccinated for mosquito transmitted viruses.

Horse with flies around its eye
Flies can bother horses and spread disease.

Flies are a natural part of keeping horses. Filth flies and aquatic biting flies are the main concerns in Minnesota. Understanding what these pests are and how they live and breed can help horse owners limit their fly pest problems.

Filth flies

Filth flies develop in moist organic debris such as:

  • Aging feces

  • Soiled animal bedding

  • Rotting feed debris


Aquatic biting flies


Roger Moon, entomology professor emeritus, College of Food, Agriculture and Natural Resource Sciences and Betsy Wieland, former Extension educator

Reviewed in 2018

Page survey

© 2023 Regents of the University of Minnesota. All rights reserved. The University of Minnesota is an equal opportunity educator and employer.