Hi, my ducks are in a paddock with my goats, they used to be on the moor in with a burn but I could never find the eggs! They do need fresh running water to suppliment their diet with associated weeds , frogspawn, buggies etc, mine dont have a burn now but a free running ditch that drains the hill so it brings down new goodies all the time. So , mine dont get a breakfast unless the ground is frozen but I feed mine a layers mash at night to get them in. I find a mash satisfies them more than loose grain or pellets. Croft land is ideal for ducks, lots of damp easy grubbable land. I used to have Swedish blue and Aylseburies but I found them too heavy for the land, if you know what I mean.. they just turned everything to mud. I now have runners that are lighter on the land. Ducks are very greedy and unfillable so you need to just watch their weight, fat ducks dont lay. I have never put grit out for anything cause I think mine have access to plenty of natural grit Another tip is for a water container inside their hut. I use an old lick bucket with holes cut into the side and a snap on lid. This means they can get their heads in the bucket to drink and preen before bed but not get into the bucket, as ducks can drown! They get stuck in buckets and cant get out , get exhausted and drown. So no open buckets etc for ducks. Also if you leave them in until 9.30 , 10.00 ish the eggs should be laid by then inside, if you cant I would put shelters around to tempt them to lay in there or else the crows will get the eggs . Good luck with your ducks.