they eat left over fish food on the bottom of the tank (if in tank)
Ducks eat grasses, wild grains, and other other vegetation. Also water snails and some insects. Ducks eat what any aquatic bird eats. Seeds, grasses and bugs on the ground and aquatic plants and little snails and other organisms in the water.
Actually aquatic snails must breath out of water. They breath from the surface.
In water where soil, algae and fish are bundant
Aquatic snails breathe through a gill. Very similar to how a fish breathes. Terrestrial snails have a lung and breathe like you or I.
Duckweed is a great food for aquatic snails.
Aquatic snails (as opposed to land snails) and fish live entirely in water - either fresh or salt, depending on their nature.
Snails love to eat bananas, but be careful with any fruits that you don't spoil your tank water (if they are aquatic snails).
No. Only aquatic snails can live in water. It is not adviseable to add any snails to an aquarium IMO anyway.
Yes. Snails have gills, which makes them able to breathe underwater.
Most aquatic snails eat either plant matter, or are scavengers. However, there are some venemous predatory snails called cone snails in the South Pacific that are highly predatory on fish; they have a poison tipped harpoon that they can launch at fish and paralyse them. There are other types of carnivorous snails as well that prey on shellfish.
aquatic snails eat algae and live plant material. if they are in an aquarium, they also eat leftover fish food. From different user: i had a water snail and the water snail liked to eat clover and grass. Be sure to wash outdoor plants thoroughly so that the bugs don't get in the water. Water snails also eat other things but from my experience, they eat clovers and grass.
This depends on the species. Some snails are aquatic while others are terrestrial. All terrestrial snails are vulnerable to drying out, and need to live in moist places.