Horses Hate Flies. Can you blame them? Aren’t you annoyed by their buzzing persistence? And, sometimes they bite! What do wild equines do to combat these pests? They will seek higher ground where breezes may offer some relief. They will roll on the ground, or preferably, in a muddy area where their skin may be temporarily protected by debris. They can shake their skin with subcutaneous muscles to discourage the insects from landing and biting. They can stand, head to tail with a companion, the constant flicking of each horse’s tail discouraging the flies around the horse’s heads. They can constantly shake their heads to shoo flies from landing.

Well, aside from the annoying buzzing, the distraction and the slight pain caused by the fly biting, what harm do flies do? Haven’t they a right to life?

No, because they do lots of harm. How many patients have I seen with an infectious communicable respiratory disease, with flies feasting on the nasal discharge? Then they fly off to another horse’s nose and transmit the virus or bacteria causing the disease?

How many hundreds of cases of “summer sores” (Habronemiasis) have I had to treat because of flies transmitting the parasite to horses?

How often are eye infections worsened and complicated by flies?

“Pigeon Fever”, also known as “Dryland Distemper”, a Clostridial disease, is spread by biting flies.

Many, many other diseases, skin lesions, and wound complications are due to flies.

Of course, flies are not just a problem for horses. Many other species, including us, are plagued and damaged by such abundant flies as the common House Fly and the Stable Fly.

So what do we do? We have been creative; Fly Swatters, Fly Screens, Fly Paper, many chemicals which can kill, or at least repel the insects (some of which have proven more damaging than the fly and others which have caused resistance due to natural selection), electric fans and, of course, protective garments. Then there is sanitation. Get rid of manure and debris.

Of all these methods, none is more effective (if used correctly), more environmentally harmonious, simpler to use, practical, and — above all — biologically natural than what we call “Fly Predators”.

These tiny insects evolved to parasitize the larvae while simultaneously destroying their hosts — the fly.