Last year I got 5 ducks because the grandchildren wanted ducks. Unfortunately a few months ago something got into the pen and 4 were killed. Only 1 large "Mama Duck" was unscathed. We added a secure area for a night pen and I got 3 young Swedish black females. The 3 Swedish are now fully feathered and all 4 are on pellet food. They have a large area (about 1500 square feet) during the day and forage on all the new grass and weeds in their enclosure and now they all have runny poop. Is this normal with all the greens, etc. that they are foraging? The 3 Swedish had formed poop when I first got them.