Yes. It's thick enough for them to do their "I want to make a nest for myself for a good night of sleep" (male and female) or "I want to make a good nest to lay eggs". Perfect! The question you need to ask yourself; is it something I want to change enough. (I think all sort of hay in big amounts lessen the cleaning) and; is it more prone to certain mites/lices ducks can have. Probably the same as any other hay. AND LESS. Alfalfa is not edible for ducks; but ducks do not eat their bedding when they are not starved. They use their hay to make a nice sleepy-sleepy place. The same thing it makes it un-edible for ducks; is the same thing why certain mites/lice do not like it! So; yes.