Starring
You and Your Students!
Script By
Vicki Cobb, Education World Science Editor
Synopsis
Do a taste test with ants: sugar vs. aspartame.
Genre
Chemistry, Nutrition, Biology
Required Props
- a can of regular soda with sugar
- a can of diet soda (check for artificial sweeteners aspartame
or NutraSweet on the list of ingredients)
- two shallow saucers
Setting the Scene (Background)
One of my earlier experiments, Sweetness and Lite, demonstrated the difference in density between regular and diet soda. Manufacturers of diet soft drinks depend on fooling people. They are counting on the fact that drinks containing artificial sweeteners taste pretty much the same as those flavored with sugar.
Are ants as easily fooled as people are? That's what this experiment is all about!
Stage Direction
As soon as spring comes, ants get active. It shouldn't be hard to find an anthill in your schoolyard or a nearby park. That's all you need to do this experiment.
Plot
Act I
Use two cans of the same kind of soda -- one "regular" (with sugar) and the other diet (with aspartame or NutraSweet). Find an anthill. That shouldn't be too hard -- ants are almost everywhere. Put a few drops of the regular soda on one saucer; put a few drops of the diet soda on the other saucer. Place the saucers near the anthill. (You can also put the drops on another hard surface -- such as a concrete walkway, a rock, or a patio stone -- near the anthill. There should be at least six inches between soda samples.)
Now wait… It won't be long before the first ant scouts discover your sweet temptations.
Ants definitely prefer the "real thing" (the "regular" soda with sugar). Within a few minutes the word on the hill is that the sugared drink is the one to visit. Talk about effective advertising!
This experiment also demonstrates communication in a group of social insects. Ants somehow communicate their discoveries to each other. Your students might want to learn more about ants to find out how they communicate.
Behind the Scenes
The molecules of natural sugars fit into an ant's taste receptors, which
are located on its antennae and in its mouth. Ants don't have receptors
that "fit" aspartame molecules, so the artificial sweetener doesn't taste
sweet to them. Since ants are not trying to lose weight (they do have
waistlines, after all), they correctly pass up the diet drink in favor
on the one that will nourish them.
The End
Ants are not foolproof! They can be tricked by drinks sweetened with
saccharine. Put some saccharine in water to test this idea.
Article By Vicki Cobb
Education World®
Copyright © 2005 Education World
04/08/2005
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