When we are working in the back yard, we let the ducks out of their pen for play time. We used to let the roam the back yard at will, but due to a hawk attack last fall, they need supervised outings. This makes sure they don't become dinner for the local suburban wildlife.
Here are our fluffy-butts enjoying their day out.

Shelley

Chrissy

Lexus

Wendy preening

Chrissy, Tweak & Shelley in the pond

Tweak
Thanks to their playing in the yard, not only did I get free fertilization and aeration service, the bug population has been seriously reduced and all the dandelions have been eaten before they could get established. Ducks sure are handy!