After a few big frosts, I dewormed the horses using "ivermectin" based paste to get the Bots. Going into fall and winter there appear to be thousnads of eggs on the front legs, and yet after deworming, I will only see a small number ( 1 or 2 per dump) of the guys. I clean poop daily, so I see pretty much every dump, and the reddish critters are easy to spot. This is the same every year. Going by the number of eggs, I would expect a to see a lot more, Where are they?