keeping duck nest safe

Question
I have a strange problem. I have a duck that made a nest under one of my bushes in the front of my home will the mother and eggs be ok or do i need to put something around the area to keep other animals away?  Also in the back under my house a cat had kittens will they bother the baby ducks after they hatch if so what can i do to help protect them?

Answer
Hi there,

Worldwide, ducks have many predators. Ducklings are particularly vulnerable, since their inability to fly makes them easy prey not only for predatory birds but also large fish like pike, crocodilians, and other aquatic hunters, including fish-eating birds such as herons. Ducks' nests are raided by land-based predators, and brooding females may be caught unaware on the nest by mammals such as foxes, or large birds, such as hawks or eagles.
Adult ducks are fast fliers, but may be caught on the water by large aquatic predators including big fish such as the North American muskie and the European pike. In flight, ducks are safe from all but a few predators such as humans and the Peregrine Falcon, which regularly uses its speed and strength to catch ducks.

However I would not recommend putting anything around the ducks nest because it could disturb the duck and she could leave the nest and not return.

If a predator came close the male duck would come out and chase the predators away.

I would also not suspect cats to invade duck nests. They are more likely to invade a smaller birds nest.

Hope this helps,

Ben.