Using sand for duck coop

[mommakurk]

I see a lot of people using sand in bottom of coop/pen for chickens could you do this for ducks as well? Would it be okay if they ate it

 

[Amiga]

A bunch of people use sand. I use it in combination with pea gravel. As long as they don't fill up on it, a little sand in their tummies is needed for chewing.