Getting Hairy

Anyone with furry pets knows the struggle of keeping their clothing hair-free before leaving the house, or constantly cleaning their furniture before guests arrive. I, myself, have two furry friends to clean up after, an Australian shepherd and an orange tabby cat. Recently, what was once a nuisance became an interesting investigation. The idea of looking at different types of hair under my Foldscope came to me when I found one of my cat’s whiskers poking through my sock. I saved it and collected strands of dog hair, cat hair, and my own hair for comparison on a deeper level.

Dog hair vs. cat hair

Left to right: dog hair, cat hair

The differences I observed between the dog and cat hair were unsurprising. The dog hair was significantly thicker, which makes sense because my Australian shepherd is coarse to the touch, while my cat’s fur feels soft and fine. Another difference I noticed was the gradient of the fur. The dog hair was thicker at the root and eventually thinned out toward the tip. The cat hair, on the other hand, seemed to fluctuate in thickness throughout. There were sections that alternated between thick and thin all the way down to the tip. I’m unsure if this is unique to the strand I chose, or if this is typical for cat fur.

Cat hair vs. cat whisker

Left to right: cat hair, cat whisker

The differences here were also to be expected. The whisker was much thicker than the hair, which is probably why I noticed it poking me in the first place!

Cat whisker vs. dog hair

Left to right: cat whisker, dog hair

I added this section to show the similarities I noticed between the cat whisker and the dog hair. Both are nearly identical in thickness and appear more transparent around the outside than the center in some sections. The dog hair does seem to have more transparent sections than the whisker, and I wonder if this is connected to flexibility. The whisker is much less flexible to the touch, so it would make sense that its fibers are more dense.

Dog, cat, & human hair

Left to right: dog hair, cat hair, human hair

This comparison again solidified my understanding of hair thickness and what it feels like to the touch. My cat is certainly the softest, my dog the coarsest, and my own hair falls somewhere in between. Like the dog hair, my hair was also thicker at the root and thinner at the tip. A new discovery made here was the transparency of my own hair. Contrary to the other strands I observed, my hair was more transparent in the center and darker around the outside. Then, I remembered something interesting! Under the brown dye, my hair is bleached. I wonder if the previous removal of pigmentation caused this transparency in the center or if this is common in human hair. It’s difficult to imagine that all of the treatments my hair has endured did not cause changes from its natural structure.

Human hair root vs. tip

Left to right: human hair root, human hair tip

To further my investigation, I compared the root of my hair to the tip, knowing how horrifying my split ends are to my hair dresser at every appointment. The strand I pulled didn’t have any obvious splits at the tip, but a closer look showed something different. The fibers are definitely coming apart not only at the very end, but even slightly further up. It seems 2020 has me unraveling in more ways than one!

Behind the scenes

No animals were harmed in the making of this post. The participants in this investigation had a surplus of fur and were generous enough to leave some laying around for me. They deserve a huge thank you for making all of this possible!

Pictured: Reginald, aka Reggie, aka The Reginator
Pictured: Diego, aka Deedee, aka El Diablo

I conducted this project as part of Professor Pringle’s EEB 321 class at Princeton University. Thank you for reading!

Alexis Kane

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