I will join the DE crowd...i mix it with limestone 1 part DE to 1 part limestone. I just pour the mixture on the ground just outside the coop door. The chickens walk through it, peck at it as a source of grit, and even roll in it like a dust bath. I have no problems with worms, lice, etc. and I think it keeps their skin and new feathers , during a molt, in a healthier state. No need to worry about withdraw times as the DE is organic....and that will keep your flocks organic status in tack if that is important to you. Make sure you use Codex or food grade DE not the stuff for pool filters although its cheaper. Caution should be used when handling any DE products; the dust is not to be inhaled and contact with the skin should be limited. Give it a try.