Flies are an ongoing problem around horses. Horse manure and soiled shavings provide the perfect breeding grounds for many different kinds of flies. Throughout all my research and how to get rid of the annoying buggers, I have come up with 3 main things you can do to help yourself and your ponies.
1. Get rid of manure!
When the stalls get mucked, what do you do with all the manure and dirty shavings?
You should avoid keeping your manure pile near the barn, as that pile will attract the most flies. The ideal situation is one where the manure is kept in a dumpster to be taken away by a disposal company.
2. Put up fly traps!
Fly traps come in all shapes and sizes. From fly sheets that the flies get stuck on to containers the flies get stuck in, these are all good ways to keep the flies out of the barn. My favorite cheap option (shoutout to my coworker Blake for telling me about this!) is very simple: a plastic bag with a couple of pennies in it. The flies think they're predators and won't come near!
3. Make your horse less tasty!
Horse getting bit up by flies? Make them less attractive! I personally use garlic powder on my ponies at work and it seems to be working! Garlic also helps reduce the size of the bumps from the bug bites on the horses. I've also heard apple cider vinegar works; I used it on one pony but, while not yet scientifically proven, many have found that it is a natural laxative, and poor pony pooped constantly!