Termite
Trails Lab
Here are some pictures of former students doing the termite lab.
Make sure kids know, by the end, how to:
Procedure:
The goal of this experiment is to teach students how to design experiments to test hypotheses. Termites lay down chemical trails for other nest members to follow. Different species of termites follow trail cues. For instance, Reticulitermes flavipes follow (Z,Z,E)-3,6,8-dodecatrienol, a chemical similar to what is found in the ink of some pens. Students are given one or two species of termite and a couple of pens, one of which contains ink that can be tracked by one of the termite species. The kids design and follow through on an experiment trying to figure out what variable elicits trail-following behavior in termites. They start out with a drawing on a white sheet of paper with different shapes made with different pens as an initial observatory period, and once they formulate a couple of questions, they pick one to experiment with, form an experimental design, and test their hypothesis. If they seem to have trouble doing this, tell them that worker termites are blind, which should allow them to form some more hypotheses and explanations for trail following.
Tips: let them draw their own experimental designs with as little help as possible. Divide the students into groups of 2 or 3, depending on how many termites are available. Generally, the more termites the better, as students tend to kill the animals when setting up the experiment. Supplying q-tips in advance also helps to control the termites…tell the students only to put the q-tip in front of the termite and it will reverse directions…not to try forcing it to change direction and inadvertently killing it. Give ample time (about 20 minutes) for experimentation with the termites and formulation of conclusions, and about 15 minutes for gathering the information at the end of class and coming up with class conclusions. The teacher should write down all observations and guesses given by students, correct or not. Give different groups different variables to test: one group just the color of the pen, another group to see if the groove makes a difference, another with different brands of pens, or another seeing if the type of termite matters.
Observations/Results of lesson:
Students responded very well; it was a success. It stimulated their curiosity, and though they unfortunately killed a good many termites, evidence of learning was present, as they themselves illustrated exactly what a control and a variable is. They got some of the feeling of forming their own experiment. However, giving different groups different variables was a little too complex—and there was not enough time at the end to combine all the data effectively. Perhaps with an AP class more different variables would be more proper. Students gave good feedback to questions posed during their experimentation period…a little prodding with directed questions helped them considerably. Next time, make sure there is someone in each group who is not afraid of insects.
Materials
-different colors and types of pens (ballpoint, rollerball, felt tip, etc)…Include Papermate pens in each set.
-blank white paper, Q-tips
-Reticulitermes flavipes termites (the ones that track the ink in papermate pens)
-Zootermopsis termites (the big ones that don’t track, if you wish to add another variable into the experiment)