My flock of 11 ducks. Six are mature and usually give me six eggs a day. The other five are a few months old and not laying yet. Their eggs are sold at a farmers market. Ducks are fun to keep and IMHO better than chickens due to the ease of keeping and consistant laying.
Great question! They are domesticated breeds, and can't fly like their wild cousins. At best they will go a few feet in the air for a short flight. However, certain individuals in my flock will get their wings clipped this fall to reduce their adventures over the fence.