Actually DE is only effective on soft bodied critters when the DE is dry. It has no effect when wet, or in the gut.
It is open pit mined, bad for the workers, at least. Look that up!
Natural' doesn't mean 'harmless'!
It is a serious irritant to anyone's lungs, including your chicken's, and yours. And it has limited to no effectiveness against mites or lice out there.
It's useful in killing mites in feeds, especially if you don't get fresh feed all the time, or if it comes in from the store that way.
I would rather use effective products when necessary, rather than spreading this stuff around at random.
Mary