This is an answer to Jim Croft's question on use of diatomaceous earth/silica dusts for insect control. I find that this is one of the most effective of the non-toxic pest control options (i.e. non-toxic to humans). It is also active for a long period of time. The only problem you have to watch out for is its use in areas of high humidity. Basically, this material is part of the family of clays which are hygroscopic. I expect though that your geographic area does not have a problem with humidity. However, you should be careful about placing the dust in areas with waterpipes, sinks, toilets, kitchens (all areas where insects do congregate), since leaks and spillage on the clay will defeat your purpose. I also would not use silica dust anywhere near computers or in places where there is an unavoidable constant draught of air--you certainly don't want airborne clay. You might also look for diatomaceous earth which includes natural pyrethrins (from Chrysanthemums) in the formula--this kills the insects more rapidly than the slow dessication effect of pure clay. I recommend that you use diatomaceous/silica dusts in basements (if dry), under shelves and cabinets, in wall cavities. Hope this helps! Prof. Linda Ellis, Director-Museum Studies Program, San Francisco State University. FAX: 415-338-2514 e-mail: [log in to unmask]