Last year in 2023 I found a baby mallard, all alone in a Kroger parking lot, surrounded by cars and no mom or nest, let alone a pond or water source to be found. Brought her home and named her Daisy. Had 2 broody hens with 10 chicks at the time, tried to put Daisy with them, but broody hens rejected her. Daisy imprinted on me very fast, following me all around. She tended to chase the chickens around. I felt bad because whenever we went inside she would wait at the door, waiting for sometimes a few hours until we could come outside. She was very friendly and cute and loved to cuddle as a baby. Went missing several times, and she eventually turned up every time except that last time. One night I went in my house to have dinner, came back 15 minutes later, and she was gone. Nowhere to be found, I looked everywhere. I didn't hear any squacking, quaking, and didn't find any feathers or blood anywhere. It still remains a mystery..... Otherwise, I would recommend taking a mallard in if you find a missing duckling, because usually in the Spring time rehab centers are overrun with animals and can't take any more in. I would call just in case, though.