bees won't leave my horse alone!

Hi everyone! So I've been working with Lambchop the haflinger for about a month now and things are coming along but as the weather improves here in the northeast, the number of flies/bees is ever increasing. Especially bees. He's been stung three times in the last week, and I can tell it's starting to stress him out. I can't even let him graze after a workout because they agitate him so bad. I've been scouring the internet but I can't seem to find anything about effective ways to keep them away. This is really becoming a hinderance so if anyone has any advice I'd really appreciate it! I feel so bad my boy.

Oh- I've tried a few kinds of fly spray and they do nothing for the bees. The flies I'm not concerned about because he doesn't seem very bothered by the flies but he's very bothered by the bees.

Are you sure that when he's outside he isn't stepping on an underground bee hive?.

Yea, I'm sure. The first time we encountered bees I that's what happened but that was out on the trail, the last few times have been at the barn up in the outside ring.

Look around for the nest, poor some gas on it and burn it.

Not really an option... for one the bees we found were a good mile from the barn. Every summer there are bees it's just that I've yet to see a horse as bothered by them as he is. I'm looking more for info on the name of a product you've used to fight them off or a recipe for a homemade repellent...

Are you sure they are bees? Bot flies and bees can be very similar.

Is it dry where you live. The bees around here are attracted by the water in the horses field. We try to put water out for them near to the hive so they have a closer source and stay away.