I don't remember all the details because I haven't thought about it for about 15 years, but diatoms are little sea creatures whose shells have a glass like texture. Apparently diatoms are quite abundant so their shells are harvested and made into diatomaceous earth. Gardeners use it around their plants. The broken shells cut like glass and thus do a number on slugs. If the shells are inhaled accidentally, they can be hard on our lungs much less ferret lungs. My son's 5th grade teacher was not aware of the dangers and exposed her students to diatomaceous earth. My son inhaled some and had trouble with his lungs/breathing for some time after. I was furious to say the least. Nancy and Sparky [Posted in FML 5651]