I think the word you're thinking of is diatomaceous earth. If you use it, be sure to get the kind that is food grade, not the kind made for swimming pools which will likely kill them. It is not the same stuff. And, DE as it goes by, will not prevent or treat mites although some people will argue the point. Some use Sevin, the insecticide, to dust them. I use poultry and garden dust (has permethrin) - not sure if its any safer than Sevin but it works. Be sure to get it under the wings (put on gloves and rub into feathers) and around the vent, keep it out of eyes, and treat bedding areas as well. Whether you choose to use DE or not - up to you, but IMO ineffective. I've caught bugs and put them in it, no effect whatsoever.