Ok, I am just learning about diatomaceous earth and I was wondering if it can be used ON ducks, not just in their pen? From what I read it can be used on dogs and cats (food grade only, right?) but what about on the ducks themselves? I don't want to hurt them. Do I need to use it on ducks? Do they get critters on them like chickens do? Do they get fleas? My duck pen is part of my dog yard (it is actually a cornered off part of the dog fence where we let the dogs out to go potty. They can't get the ducks though, but fleas can go through the chain link fence). I saw two of my new ducks scratching at their heads today. It was pouring rain though, so I haven't tried to catch them and see if I see any fleas. But, I will tomorrow, when the sun is out and the duck pen isn't so mucky! I can just see myself falling on my butt chasing them!! LOL Also, I read it can be FED to dogs? It is supposed to help with internal parasites, which I assume would be worms that dogs are prone too. Can it be fed to cats too? Does it take care of tape worms, or just hooks, rounds, etc.? Thanks everyone. I appreciate any and all information. Kathy Edited to add: My dogs are on frontline, but I know that not ALL the fleas are gonna die, so there may be "some" in the yard. We haven't actually seen them or have any get on us, but I know it's possible.