Adding two ducks to a flock of 6 chickens

[Ccort]

I'm thinking of adding two ducks to my flock. They would live in the same coop and spent about half the day free ranging, just as my chickens do. They would also be in a run when not free ranging, with the chickens.
While I would have a pool for them OUTSIDE the run, would it be an issue to not have a pool inside the run? I'm concerned that spilled water will cause lots of flies.
For the roost, is there anything special a duck needs?
Acclimation...in your experience, have the ducks been able to acclimate well with the chickens? Was it a lengthy process? Bullying?
Lastly, if you house ducks with chickens, what do you feed them?

 

[aart]

would it be an issue to not have a pool inside the run?

Ducks don't need to swim, but they do need a waterer deep enough to rinse their nares(nostrils).
They'll still make a wet mess which isn't good for chickens.
Male ducks with chickens is risky business, if a male duck mates a chicken his corkscrew shaped penis can kill the chicken.
I've never wanted ducks, but if I did I would keep them in separate housing.