Fleas on chicks - organic treatment?

[spatulagirl]

I have a broody that was sitting on eggs in a staggered hatch. She wasn't dusting at all. When she hatched out the last three eggs, I moved her and the chicks to the garage into a large pen. She has two dark colored chicks and one Wheaten Americauna. I have noticed a light colored flea two days ago on the light chick and popped it. Today I noticed two more. The hen won't let me pick her up to inspect her. So I need to treat them.

Would just DE work?

Also, I plan on cleaning out the coop today. Can I just dust everything with DE like I normally do before putting in new bedding?