Today, 3 of my 4 baby runner ducks (5 weeks old) vomited on me when I picked them up. It was basically loads of dirty looking water coming out of their bills and all over my clothes! I guess it was probably the muddy water they were drinking, but I am confused as to why they would bring it up in this way. Their crops seemed to be squishy and soft (probably full of water). they went straight back to the water and drank loads of it. I was feeding them peas and they did not puke up the peas, just the fluid. This has never happened before and they love their peas. Funny how puking did not affect the pea-love! They free range and eat grass and I am feeding them on chick crumbs with added niacin and grit. They have been feasting a bit lately on the layer's pellets which is for my chickens - could this be relevant? They free range over my lawn with my chickens and tortoises, and they all walk in each other's muck, but they are all healthy with no worms or anything. Any advice on what caused it and how I can prevent it happening again (besides not picking them up of course). I used 2 hands and did not squeeze tight or anything around their necks. Bit of a mystery to me. By the way, all the ducks appear healthy and happy and no discharge from eyes, nares, or vents.