Hi Beulah, I assume from your post that you've probavly read this thread about Red Mite control http://chat.allotment-garden.org/index.php?topic=45792.msg536986#msg536986
A word of caution on sprinkling Diatom or indeed other dusts in the litter especially if the chx can walk in it. Chx are particularly susceptible to airbourne respiratory diseases and a single dust particle can carry enormous numbers of viruses (I think i've seen figures in the millions quoted) not to mention the undesirability of the mechanical effects of dust on the lungs. We all know about farmers lung, asbestos and coal dust caused diseases it therefore makes sense for you and your chx to try to keep dust down to a minimum. I use Diatom too in my red mite control and I think it's reasonably effective so i want to contine to do so, but to cut the dust down I now only apply it as a slurry painted onto the perches and into corners where I know red mite have colonised in the past. It dries to a light off white coating which isn't too dusty but non the less still seems to work. It also dries the droppings and stops them sticking to the perches where they fall through on to shavings on the floor where the chx can't walk. To mix the "paint" add the diatom to the water and mix as you increase the concentration to a creamy liquid slurry. Actually I use a disinfectant base rather than water, Vanodine W18, which i hope kills any viruses /bacteria too. I don't know for sure that his is any use as a disinfectant once it has dried but seems to make sense.
For more info on the possible dangers of using Diatom or similar products see
http://www.shagbarkbantams.com/contents.htmBest of luck