Found this........ The Original Dust Mite Story Soon after I purchased a 200mm f/2.8 lens last year, it got a really large white spec on one of the optical elements inside. This spec was quite a bit larger than any other piece of fluff in any other lens I own. It was quite disturbing but did not affect the beautiful pictures that this lens took. Last week, I observed to my horror a dust mite crawling on this very same optical surface. It walked directly towards the spec, ate it, then walked out of site. I watched it happen in amazement. The lens is pretty clean now except for a single fiber which came from the internal baffle. The little mite has not reappeared since and i've disinfected quite a bit of stuff becasue of my new discovery about dust mites...i've never ever seen one before this...you sure can see anything when it's inside of a lens! I can only hope it did not lay eggs inside of my lens. I hope I can train these suckers so that I can sell my new internal lens cleaning technology. Sick.