There’s nothing like reading a little E.O. Wilson to uncover new creatures in your life. In this case, we learned about the commensals, symbiotic organisms that live on the bodies of other species or in their nests without helping or harming them. Commensals are free riders in cases where cost is not an issue.
Wilson explains that most of us carry two such commensals on our foreheads- mites with wormlike bodies and spidery heads so small that they are almost invisible to the human eye.
Demodex folliculorum dwells in the hair follicles. Demodex brevis dwells in the sebaceous glands.
If you want to get intimate with your forehead mites, Wilson explains how you can do just that:
Stretch the skin tight with one hand, carefully scrape a spatula or butter knife over the skin in the opposite direction, squeezing out traces of oily material from the sebum glands. (Avoid using too sharp an object, such as glass edge or sharpened knife.) Next scrape the extracted material off the spatula with a cover slip and lower the slip face down onto a drop of immersion oil previously placed on a glass microscope slide. Then examine the material with an ordinary compound microscope. You will see the creatures that literally make your skin crawl.
Source: E. O. Wilson, The Diversity of Life, p. 177
Apparently, the Japanese even have special cosmetic products guaranteed to kill these “beauty-destroying” mites. So here’s a science project idea to help you learn more about forehead mites and their habitat requirements- not sure if it’s been tried before, but we are going to do so.
PURPOSE: To find out what forehead mites need to live on our foreheads.
HYPOTHESIS: Skin oils trapped in hair follicles and sebaceous glands keep forehead mites happy.
EXPERIMENT: Run a sample of forehead mites on your forehead. Count the number and note the integrity of each under a microscope. This is your sample. Then assemble several cosmetic products which claim to remove oil from facial skin and plan to use one 1x a week for several weeks. For example, you can run a control swab and then use witch hazel for week one, a popular astringent for week two, a product with salycylic acid for week three, and a chamomile tea bag for week four.
Run another swab after use of each product. Note if the mites are fewer. Try another swab at a later point during the week and see how quickly (if at all) the mites return based on the various products used. There are many variations- and loads to discover.