X2
You def do not want broken legs or infections!! One thing that I've learned as I have aged is that there is nothing I hate dealing with more than an issue that would have been preventable.
Do heed Miss Lydia's advice. Do read her suggested article. If you've committed to raising ducklings, then you have accepted (and agreed to deal with) the messes. You need to keep your ducks in a clean and safe environment, just like all babies of any species requires
BTW, ducks in general, have very skittish and jumpy personalities. I believe it stems from being a prey animal (like other animals' food)... I think it's good that you are asking questions, but honestly I am a bit concerned about how these ducklings came into your possession. I believe that in nearly every instance, ducklings will always do better with their mother to raise them. It's nature's way.