Full STEAM Ahead

All science starts with wonder, and intrigue, and this is certainly true in the study of animals, zoology. Most wild animals keep their distance from us, and try to minimize their interactions with us. Mosquitoes are one major exception. In the summer and early fall, they fly towards us and seek us out. Though we don't want their attention, it makes them especially interesting, and raises many questions. How do they find us? Why do they bite some people more than others? How do we get them to leave us alone? All of these questions can be used to teach young people that the steps used to create scientific knowledge are fun, (which is the most important single concept in science education.) When we make an observation, (such as "Mosquitoes fly towards me an land on me") and ask a question, (such as, "How do they find me?") the next step is to read what other scientists have already learned. I will summarize that for you, so that you don't have to seek it out. Scientists have already written papers that show mosquitoes don't have the kind of eyes that allow them to recognize humans by sight. Instead, they use their sense of smell to locate where the nearest warm blood is. Mammals like us, breathe out carbon dioxide in concentrations that are heavier than are normally found in the air on planet Earth. (Plants release both oxygen and carbon dioxide, but when we exhale, we make dense clouds of this gas.) When a hungry mosquito detects some carbon dioxide in the air, they fly towards it. That only gets the mosquito in the general area of the meal they seek. They also can smell with their "chemo-receptors" other chemicals that are on human skin. Researchers have found that the same chemical that makes socks stinky after being worn several days in a row, is one of the most important chemicals that mosquitoes use to find dinner. When a mosquito gets really close to you, they can feel the heat coming off of your skin. This heat coming from your skin is what mosquitoes use to find a patch of you that is not covered in fabric, and to land. Whenever we read what other scientists have discovered, new questions come to mind. For example, "Whose dirty socks are most attractive to mosquitoes, me or my mom's?", or, "If I wear my socks for three days in a row, are they more attractive than socks I only wore for one day?" are silly questions that might be a fun to test. What we need is a mosquito trap. These can be made by cutting a soda bottle in the same way as seen in this video. https://www.youtube.com/watch?v=Y1eGOwLVhTc. (Note that the creator of this video, Mr. Invento, suggests that mixing yeast and sugar water will produce a trap that can control mosquitoes in your back yard. This is based on the correct idea that sugar and yeast will produce carbon dioxide, which will attract some mosquitoes. (However mosquito scientists, Doug and Ellen Bidlack, who work for the state of Massachusetts, explained to me that this trap won't capture enough mosquitoes to make a difference in how many times you might be bitten. However, Mr. Invento's instructional video on how to build a mosquito trap is very clear and short.) This scientific test will require two identical socks, (cotton socks are best) one that you wore for three days, and one that you wore for only one day. (The socks may be ruined in this experiment, but speaking as a nerd Dad, it may be worth the investment in socks to plant the kernel of science joy in your child.) You will put each sock into its own trap. Place each sock at the bottom and cover it with water. Mr. Invento uses way too much sugar in his mix, so put two tablespoons of sugar and a teaspoon of yeast into the bottle before you seal the traps with tape. Set each bottle out in your back yard and leave them there for a week. Ideally, a third bottle with no sock, just yeast and sugar water, would also be set out, so we can compare it to the sock filled bottles. You may need to add water periodically to the trap, depending on weather conditions and the amount of water you start with, so check them occasionally to be sure that they don't dry out.) Almost all science requires counting to see if there is a difference between treatments. Are there mosquitoes in any of the bottles? Are there more mosquitoes in one of the bottles than the other ones? (We have been having a bit of a dry summer, and mosquitoes breed in the water, so the numbers of mosquitoes flying in the air may be less than in a normal year. My hope is that you still get some mosquitoes in your traps.) The next step in the scientific method, is analysis. One general way to paraphrase the analytical question is, are the numbers really different? In this experiment, imagine we see five mosquitoes in one trap, and only three in another trap. Does that really mean that one trap was more attractive than the other? Probably not. It might just be chance that there is any difference between the numbers. To overcome this sort of problem, scientists repeat any test they run, and look to see if they get the same kind of result. To be sure you have gathered strong evidence that points you towards truth, you might need to run this test again. (I know, the smell of thoroughly rotten socks might seem like an increasingly expensive investment in your child's education.) A less smelly experiment might be created to determine whether cooled skin was less attractive to mosquitoes. And sometimes "thought experiments", ( i.e. experiments that you talk about and design, but don't carry out) can be both pleasurable and educational puzzles. Can you think of a way to set up an experiment so that you can learn if cooled skin is less attractive to mosquitoes? Can you get one arm of the same person cooler than the other arm? How would you do that? Is it possible mosquitoes are more attracted to one arm of a person more than their other arm? How can you repeat your experiment to make sure that any differences you see between arms is only caused by one arm being cooler than the other, and not based on any other possible difference? There are many questions you could ask based on things you and a child observe together. To start this game, when a child shares an observation, you can ask, "How could we design an experiment to learn more about that?" This can encourage a life time of inquiry. If you run this experiment, I would love to know the results. And, if you come up with interesting thought experiments, I would love to know about them. You can write me at booksfromvermon@yahoo.com. Please put the word "Fun" in the subject line. Rolf Parker-Houghton lives with his wife, the artist Cynthia Parker-Houghton, and their son in Brattleboro, Vermont. To see what they are up to check out the UniversityofBrattleboro.com online.