This is some COOL stuff!!! It looks and tastes like chalk dust.  It is ground up like flour diatoms (one celled plants that lived in the ocean floor)  It works by basically, cutting the bugs/parasites and then they experience "death by dehydration," so they don't build up a "tolerance."  

When someone first tried to tell me about "eating dirt," I was NOT interested.  It wasn't until I started using it when we first got chickens in the spring of '09, that I started using DE to keep the smell down in their litter.   In the coop, the smell is under control with just a weekly addition of more pine shavings and DE and "harvesting" the pans under the roosts.  Then, I started adding it into the food of the chickens, cats, dog and myself.  I mix 1# in a 50# sack of chicken feed, and sprinkle all over the roosts, the  coop and exercise pen.  For the dog and cats, it just gets mixed into the kibble/water.  I mix mine with a little water and just slam it down with a water chaser. They say the human body can host 100 parasites of which only 10 are normally tested for.  It seems to help mine and my dogs arthritis and my over 50 "bursting into flames" is helped as well. 

DO NOT USE POOL GRADE DE - USE ONLY FOOD GRADE!
Best price is usually the feed store Richfield Feed  ~ 22 bucks for 50# sack
Do NOT breath this or any dust.  Be careful about the vacuum as it will jam your filter.

More info and dosages -  http://wolfcreekranch1.tripod.com/defaq.html