Seriously, people are that stupid. Of course, a Darwinian approach might work, but that idea never seems to be all that popular...
We haven't had any issues with mites or other crawlies yet (knock on wood), we mainly try to keep the litter dry in there, and Karin does a light DE treatment on the run every few months, whenever it starts looking like the straw in there needs to be changed, we take it out and dust a bit. We don't use DE inside the coop though. I'm not a big fan of preventative poison use, it's not that healthy on the chooks, and it might help build up a tolerance. Keeping a close eye on the coop is a better idea in my opinion, and then killing everything at first sign of trouble. I know some people use that corrugated cardboard as a mite indicator (the stuff with a wave shape between two flat surfaces, it provides an excellent home for crawlies, so having small pieces of it in a few places in a good way to monitor the situation.
I wouldn't use wormers without indication of trouble either. Then again, our climate sort of keeps the pest population slightly lower.
I think we might go buy a trail cam tomorrow. Turns out, they're not really all that expensive after all... If I can get the store to do price matching, it would be cool. I found one that seems OK for 120e close by, or 90e on the other side of the country + 10e shipping. 20e for impatience isn't that bad, but if I can get them to match the 90, I would even save the shipping charge. We'll see what they say.