From the Centers for Disease Control (CDC): Baby animals, including baby chicks and ducks, are sometimes given as gifts or put on display at Easter. Young birds often carry harmful bacteria called Salmonella. Each spring some children become infected with Salmonella after receiving a baby chick or duckling for Easter.
Children can be exposed to the bacteria by simply holding, cuddling, or kissing the birds. Others at increased risk include persons with HIV/AIDS, pregnant women, the elderly and other immunocompromised persons.
From the animals' standpoint, many people are unprepared for caring for adult chickens, ducks, or rabbits. Studies show that up to 95% of baby bunnies purchased for Easter never reach their first birthday. Baby ducks are often abandoned in ponds, where they will starve to death or be killed by predators when the pond freezes, as they are unable to fly like their wild cousins.
Please, don't buy animals and if you don't want to keep them for many years! It puts your children at risk, and sets a bad example for them for taking proper care of pets.