We recently moved our horses into our new barn we built and have had an invasion of fungus gnats. For those that do not know what I am talking about, they are the tiny little gnats that instantly swarm and cover horse poo. We are being taken over by these little boogers, im talking by the millions. Covering the walls, the stall doors, swarming in the air, etc. Its awful. Our stalls are a more open concept, so im guessing thats why they are so bad. Anyone have any ideas on what to spray to keep them away? Or at least keep the numbers down? Anything I could feed the horses to make their poo seem less attractive?

Where do you live?  WE have gnats but I have never heard them referred to as fungas gnats.

We are in NC. They are not the biting gnats that bother the horses, they are the poo gnats or as google calls them "fungus" gnats