Water is all around us: we drink it, we wash with it, it falls on us as rain and it flows past us in rivers and streams. Water is life! This can be seen even in small areas of water. Let's take a look at some standing water: there are ponds, pools and lakes everywhere, so there's bound to be one near you, and they provide a habitat for all kinds of interesting plants and animals ts.
How do creatures like pond skaters manage to skim across the water on their long legs?
You will need:
• 2 small bowls
• Kitchen paper
• 2 metal paper clips
And here's what we do!
Fill the two bowls with water. Add a drop of detergent to the second bowl and give the water a stir. Very carefully lay a small piece of paper on the water in the first bowl, then carefully put a paper clip on it. Repeat this with the other paper clip in the second bowl. Watch what happens in the two bowls.
In the first bowl with the water, the paper sinks after a while and the paper clip floats on the top on the water. The clip rests on the skin of the water and pushes it down a little. In the second bowl with the detergent, the paper clip sinks along with the piece of paper.
What has happened?
The paper sinks because it has become saturated with water. Metal is heavier, but it floats on the water because it is supported by the skin of the water – just like the pond skater. This skin forms because the tiny water particles on the surface are attracted to each other. Soap and detergent destroy that skin.
Watch a pond skater on a pool of water. You will see that his long legs slightly depress the surface (or skin) of the water.
If you'd like to find out more about ponds and the creatures that live in them, order a copy of this great brochure that's full of crafting ideas, puzzles and lots of suggestions for things to do near a pond.
You can order the brochure from the Haus vun der Natur: natur&ëmwelt a.s.b.l.
5, route de Luxembourg
Tel. 29 04 04-1