Yesterday we added 2 indian runner ducks to our flock of chickens. The chickens don't bother them, but we are worried as the ducks don't leave the coop, and each time i've gone to check on them they are sat in the back corner and not eating or drinking. I threw some bread by them and they ate that, but didnt eat anything else, then we shooed them out and they stayed out all day and ate grass. Is this normal for new birds?