Cushioning Hedgehogs

Yesterday, I showed an image to my physics class of a hedgehog curled into a ball and the description:

The spines of a hedgehog obviously help protect it from predators. But they serve another function as well. If a hedgehog falls from a tree—a not uncommon occurrence—it simply rolls itself into a ball before it lands. Its thick spines then cushion the blow by increasing the time it takes for the animal to come to rest. Indeed, hedgehogs have been observed to fall out of trees on purpose to get to the ground!

Pearson Education 2019

It’s the physics unit on impulse and momentum change.  Air bags, seat belts, and crumpling bumpers are more typical examples used to demonstrate the relationship between impact force and impact duration, the idea, increase the time duration of the collision to reduce the impact force (cushion the blow) while the moving body’s momentum drops to zero.

Hannah appears interested, raises her hand, “I have a hedgehog story.  My cousin had one.  She named it Bruce Quillis.”

“And?”

“That’s my story.  It’s not really a story.”

“Class, other hedgehog names?”

“Quill Smith.”

“Quill Ferrell.”

“Prince Quilliam.”

Seated next to Hannah, Stretcher says, “I have a story.  My aunt once killed a hedgehog by drowning it.”

“That’s one sadistic aunt.”

“No, wrong idea.  She drowned it in the bathtub.”

“And how does the bathtub make her less sadistic?”

“She was giving it a bath.”

“Hedgehogs require grooming?”

Stretcher says, “She got distracted, left to do something else.  Hedgehogs can’t swim.”

Someone else says, “They’re soft if you pet them in the right direction.”

I look at Blatt’s tablet and see a paused Youtube video, titled ‘Hedgehogs Swimming’.  Blatt turns his tablet to Stretcher, “Hedgehogs can swim.”

Stretcher shrugs, “Baby hedgehog.  They can’t swim.”

Rayva says “Hedgehogs are illegal in Georgia.  I tried to get one.”

I ask, “Before or after you discovered they were illegal?”  Rayva is silent and drops her head, acting like she’s taking notes.

Hedgehogs are much smaller than, and unrelated to, porcupines. Hedgehogs are not considered rodents, they’re insectivores.  Hedgehog spines do not detach like a porcupine’s quills.  Porcupines that shoot their quills like projectiles are a myth.

Young hedgehogs may lose their spines in a process called ‘quilling’ but they’re replaced as they age into adults.  Spines may be permanently lost due to disease or under stress.

Sally dug into her backpack and extracted a plastic bag containing her blood-stained wisdom teeth (permanently lost to the dentist just yesterday) and asked if anyone would like to see them.  She said her blood was taken and centrifuged (referencing first semester’s unit on centripetal forces) to separate the platelets, apparently used in her recovery treatment.

In Britain, wild hedgehogs are considered threatened by habitat loss and vehicular hedgicide.  In America, it is illegal to keep a hedgehog as pet in California, Arizona, Georgia, Hawaii, Maine, NYC, Pennysylvania, and Washington D.C.

Hedgehogs are used as croquet balls by the Queen of Hearts in “Alice’s Adventures in Wonderland.”

The most common hedgehog pet species are hybrids of the white-bellied hedgehog and North African pygmy.  Hedgehogs can be socialized by tender pet owners, taught to trust being handled by humans without curling into a prickly ball, but by nature, they’re loners and only ‘hook up’ for mating.

Cross a hedgehog with a poodle to smooth their coat, what would you name it?

“Poodlehog.”

“Hedgoodle.”

“Hedgie-poo.”