A friend had a bad hatch and only 1 duckling hatched successfully. I had time off and was brooding 2 special needs chickens at the time, so I agreed to take the lone duckling. Well, the duckling is extremely attached to me. She doesn't like when I'm out of sight. She used to scream her little duckie head off, but she's calmed down a bit lately.
It's working ONLY because I'm still off right now and can spend every waking moment with her. She gets swimming time in the morning in the bathtub or in a mixing tub in the front yard. Then she gets exercise time in the playpen while I clean her cage. Then I take her out with me in a little carrier if I have work to do in the yard. Otherwise, we hang out in the house while I do housework. She gets foraging time in the afternoons. It's a full time job.
I'm headed back to work soon, and my son is going to stay with her until I can find her a friend. She can't be alone, and she's not used to other ducks, so I don't think I can put her with my other 5 ducks. She and her future friend are going to get special housing in my front yard.
I just don't recommend it, personally. I'm worried she will have serious separation anxiety while I'm gone.