Having a flock of feathered friends in your backyard is all the rage, thanks to the urban farming movement. But what do you do with your flock of waterfowl at night? Just because you live inside the city limits or on the very outskirts of an urban development doesn't mean that those nighttime predators - coyotes, opossums, and raccoons - aren't lurking around waiting to snatch a tender duckling. Sadly, even your neighbor's dog, since most dogs are no longer acculturated to protecting livestock, can be a menace to your feathered family.