To stop flying at your riding school, you can purchase a Knock off fly bag. These bags are easy to hang and contain an attractant that is very attractive to flies. This substance is odor-free for humans, but flies come off in no time. The well-known FlyNip lure is used for a Knock off fly bag. Knock off fly bags can hold about 55,000 flies, so you don't have to worry about them for a long time after hanging.
Buying a Knock off fly bag
You can buy a Knock off fly bag in the webshop of MHS Equestrian. These bags are already provided with the attractant, so you only have to shake a layer of water to start catching flies. The built-in entrance opening makes it impossible for the creatures to escape after being caught. Make sure you hang the bag in a place in the sun where wind can also come, so that the result is even better.