I’ve been seeing these small nat like flies landing on my horses and I’m afraid they’re biting flies. I can’t see any marks and the horses don’t seem affected but I can’t tell for sure. Is there anything I can apply to them that won’t be poisonous?
There are many flying insects which can cause horses to be uncomfortable. Most are biting flies of some sort like no-seeums, mosquitoes or horse flies. There are several nats which don’t really bite and it could be one of these you see. If you insist on doing something, apply some Permethrin which is labeled for use on horses and other animals. It’s odorless and won’t be a hazard to them when used at the labeled rate. This should stop the “nats” you’re seeing as well as any other flying insect.