A pond can be as small as the kind you find in a garden. It can be a large area in a public park. But whatever its size, it gives a place (habitat) for wetland plants and animals to live. They don't just live in the water. They live in the banks, on the plants that grow out of the water, and so on. You can probably think of many pondlife examples, such as water-lilies, frogs, dragonfly and herons.

Some plant-eating animals like geese, do not live by the pond, but eat the wetland plants. When pond plants die and fall into the water, they decay, and then a large number of invertebrates (things like beetles) then feed on the decaying plants. These are, in turn food for fish, dragonflies and herons. This is a food chain. In the open water of the pond there will be other food chains. Algae (microscopic green plants) will float in the water and be food for insects, who are, in turn, food for small fish. This variation in habitat in and by a pond is why a pond can support a very large number of species compared to, say, a nearby pasture.

The problem of ponds is that they are small. It is easy for them to become polluted and to be destroyed by building and other things that people do. All of these things will make life harder for species in the ponds.

Some ponds are natural, but many are now artificial. It is very important to dig an artificial pond correctly in order for it to be home for a range of living things. That is, it is best if the sides are gently sloping, and not all vertical. At a minimum one side should slope gently. It is amazing how many more birds, for example, can then come to it and use it as a source of drinking water. If the sides are all steep, the birds cannot use it. Similarly, one end of the pond should be deeper than the other end. Then plants which like deep water and those that like shallow water will all be able to grow. If you go to an aquatic garden centre you will see that the plants for sale are marked out by depth of water.

It is also good to allow the pond to partly dry out in the summer as it would do naturally, and not fill it back up all of the time. This more natural management is what many wild things are adapted to. Also if you direct rainwater from a roof to a water butt and then connect the water butt to the pond, it will fill with natural water and not chlorinated water from the mains. The butt allows you to control how much water you add, and when. It is like a mini-reservoir. Similarly, if this system causes the pond to flood over in winter, then this is not something to worry about, for it is closer to what would happen naturally. All of this is easy to manage if you have a garden. Ponds can also be built in schools.