This activity is from Discovering Insects (lesson 8, part 1).
We've adapted it for the web to enable you to try it at home
with common stuff from around your house.

INSECTS
LESSON 8

Did you know there are bugs that can walk on water?
They're called pond skaters, or water striders. Pond skaters are not exactly floating on the water. They stand on its surface.

You can see how this works if you use a paper clip for a pond skater.

Pond Skaters - also called Water Striders  


A clean bowl or large cup filled mostly full of water, and some small paper clips.
Start by making a paper clip elevator, like this:
     
Now try to lift a paper clip, keeping it balanced on the shelf of the elevator. It takes a steady hand. Lower the paper clip into the water with the elevator. If you're careful, the paper clip will stay on the surface.


Why doesn't the paper clip sink? Because water has surface tension, which makes it a little bit difficult for something to break through the surface, whether it's a paper clip or a pond skater.

If you have liquid soap handy, put a drop in the water near the paper clip. Soap reduces surface tension. What do you think will happen? Try it and see.

Other insects don't have the ability to stand on water. If they crash land in the water, they break through the surface and are trapped by the surface tension. They become prey for the pond skaters, who skate over and suck their juices like a milkshake!


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©2001 by Stratton House

The above lesson is from the student worksheets. Additional notes and questions are given in the parent guide.


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