I have a bad feeling about the whole thing. The kid said he will take care of thing the next day (including food). You cannot do that with babies. Worst some people suggested to keep them and to make pets out of them. I didn't post, because I did not like the way it went, plus we had a wild fire on our property to take care off. It's out now, but it was hard work even with the fire department. Some people did the right thing by pointing out that it was wrong and illegal. I bet the mother duck is now looking for its kids. It sometimes takes hours for them to come back looking.
I once caught a wild mallard duckling. I did put it into a cage where I found it (my property's parking lot). It called for over 4 hours and nothing. We later found dead mom and one dead sibling on the highway in front of our property. We took the duck in and raised it, with the confirmation of the local officials that we could do it. The deal was to keep it separated and interact as little as possible. They did not have any other resources available, and they do it this way all the time as long as they feel comfortable with the people doing it. You must call them first regardless. We did raise it with almost no interaction and it still started to follow us around. We did let it start taking flight practice, and it was wonderful to watch. The end of the story is that it later joined the wild ducks around us and migrated with them. That is how it should be. Not just starting to feed it and later dumping it on the local pond as the kid wants to do.
Katharina