So, I'm fairly new to the duck thing. Prior to my four pekins, I had one rescue Musgrove drake, that's all the experience I have with ducks. So my question, 1 of my 3 girls has recently started laying. I picked up some oyster shell from the feed store, but I don't know how to give it too them. Can it be given to all the ducks? Also, I keep a bunch of food outside all day for them to eat when they like, so individual feeding isn't an option. Also, does it need to be ground up further, or can they eat it like it comes? Just seems kind of sharp and jagged to be eaten whole, but I don't know. Any advice is appreciated.