Help with diatomaceous earth

We bought DE a few weeks ago (YES we did get the food grade DE) , we have four chickens. We have been putting it down on the ground for them for while they are taking their dust baths but I know you can use it in multiple ways, but I am just not sure which is the best way to use it. The ground of their pen is all dirt there was grass but they have killed it all off, when we put it down on the ground we don't put a lot as we are not sure exactly how much to use, so we basically put it all in one area, use a rake to kinda mix it in with the dirt in the area and leave it be. What are your suggestions?

How much ground should we cover with the DE? All of it?

Should we put it on their food? How much per pound? We have a 10 pound hanging feeder which we don't fill all the way due to living in Fl where it is always moist and we don't want the food to go bad.

Can it be put directly on the chickens? How much?

Any other ways it can be used would be greatly appreciated!!

We also have one chicken who is has the run of the area (we found her and she has claimed our house as hers) what would be the best way to use it for her? She is usually around our house, spends most of her time underneath our storage trailer so there is not really a way to get under there to sprinkle it around, her nesting box is on the porch, and her food is next to the pen the other four chickens are in. (We can not put her in the same pen as the other four as they are only 14 weeks old and she is not used to them and attacks them when we put her in).

TIA!!!

DE can be useful as a preventative for killing some chicken pests.

It can also be a lung irritant and chickens respiratory systems are delicate, so I don't put it dust bathing areas(plain soil with occasional wood ash) or on the birds bodies. If you have an infestation of lice/mites on the birds, it's not going to get rid of them.

It is useless once it gets wet tho(it works primarily as a desiccant), so putting it all over the ground is kind of a waste of money, in my opinion. Putting it in their feed to kill internal chicken parasites is pretty much a fallacy, it is put into livestock feed to kill any bugs that might be in the grains after harvest while it is stored....it may even already be in the feed you are using.

I do sprinkle some in the cracks and crevices of the nest boxes under the straw bedding and under the edges of the vinyl flooring in my coop as a preventative.

JMHO

Don't put it on the ground in the run. It kills insects, and you want insects in your run so they can eat them!

Sprinkle some on their bedding in the coop where you want pests to die.

Then if you suspect internal parasites sprinkle some on their food.