yes only if u disturb them in anyway or get to close to them or try to take their eggs
yes ducks can bite you if you get too close
Some species are.
Yes if they have a chainsaw
It's not harmful at all.
they arn't
i dont kow
it is harmful...affects human health!
Ducks actually do not have any known harmful effects; however, environmental issues can have harmful effects on ducks and other birds. An oil spill is one example of how they can be harmed by changes in the environment.
A material that can be harmful if not properly disposed of is hazardous.
Food is essential to human life and health. All humans should have access to a variety of foodstuffs that contain the vitamins and minerals essential for human health. But too much food is harmful to humans and every effort should be made to avoid the possibility of food impacting negatively on human health.
Extremophiles are a danger to human health. Extremophiles can be a danger to plants.
Some bacteria are beneficial to humans, and some bacteria are harmful to humans.
Radon gas.
See "How does ozone affect human health?" in the "Related questions" section below.
hazardous wastes