Summarize this article in one sentence.
Ducks love to swim, and they'll start as soon as the first day after they hatch if you let them. Do not let them swim unattended. Baby ducks are covered with down, which isn't waterproof, and their bodies are still too fragile to cope with swimming alone at this stage. The paint roller tray makes a great environment for starter swimming.  You can supervise them closely, and the slope in the tray creates a little ramp to help the ducklings get in and out safely.  Don't let the ducklings swim too long, or they'll get chilled. When they're done swimming, dry them off gently and place them back in the brooder so they can warm up. You can also let them sit on a heating pad covered with a clean towel for a few minutes. When ducklings are fully feathered with their waterproof, adult feathers, they can swim without your supervision. Depending on the type of duck, full feathers should be in place by 9-12 weeks of age. Make sure the ducklings are supervised at all times while they're still growing their adult feathers and learning to swim, particularly if letting young ducks swim in an outdoor pond. Older adult ducks that may share the same pond or water source may try to drown or kill the younger ducks. Ducks, particularly when young, can be targets for predatory animals. You can free range your ducks when they are adults, but remember you may lose ducks occasionally to predators. You should make every effort to keep them safe from predators.  If you're raising ducklings in a garage or barn outside, make sure no other animals can get near them. Wolves, foxes, and even large predatory birds could harm your ducklings if you aren't careful. Ducklings raised inside your home need to be kept safe from dogs and cats, which may try to attack or even play too roughly with the ducklings. Once the ducklings move from the brooder to a larger pen, make sure there's no way for predators to get in. It's tempting to cuddle with the sweet, fuzzy ducklings, but if you get too close to the ducklings, they might imprint on you too strongly. To make sure your ducklings grow up into an independent, healthy adults, enjoy watching them play with each other, but don't join in the fun too much. Once the ducks are too big for the brooder, move them to a large dog kennel or a shed with a latching door. Feed them adult duck feed and let them spend their days swimming and splashing in a pond. Make sure to bring them back into their shelter at night to keep them safe from predators.

Summary:
Encourage the ducklings to swim. Make a little swimming pool out of a paint roller tray. Allow adult ducks to swim unassisted . Be wary of older ducks. Keep ducklings safe from predators. Keep some emotional distance from the ducklings. Move the ducks to a larger space.