Marking on ducks.

[BelovedBirds]

Ill have to look into those! Do I need to worm mine? Oh boy

Its up to you really, if you have a lot, you may want to consider it. I haven't bothered with it personally as I only have a couple and I monitor their weight, egg production and faeces so closely. That said, I'm considering testing them for worms occasionally to be on the safe side.
From what I've heard, worms aren't quite as common for ducks as they are for chickens.