DO NOT use diatomaceous earth. If the package says that humans should wear respirators when handling DE then it definitely shouldn't be put in with birds. You can get silicosis from handling it as well.
DE is a crystal that has minute sharp edges on every angle, it is terrible for your lungs to breath it. Now imagine if your lungs were only the size of a quarter?
Further it's been proven to only be somewhat effective and usually only at preventing internal parasites carried by other bugs.
Use sevin dust in their dust bowls. Sevin dust is a chemical but is proven safe for use around all types of animals and humans. It's much safer and healthier for everyone involved.