Cool water swirled around my rubber boots as I waded out into the dark, star-studded lake. A sense of peace began seeping in with the chill. Then, SPLASH! From out of the darkness came the unmistakable sound of a beaver slapping its tail in alarm. Of course I looked up, and my light caught his swimming form in the beam.
I chuckled at my own surprise. Then immediately I began thinking of how I would tell this story to the kindergarteners during my MuseumMobile program the next morning as we passed around the dried beaver tail.
Beavers are not my favorite animal. Their drab, oily fur, plodding manner, and lumpy design don’t inspire the same feelings of wonder in my heart as a cheery little chickadee, rangy wolf, or glittering dragonfly. But over the years, I’ve come to enjoy teaching about them nonetheless.
During an internship at Acadia National Park, we included beavers in a fourth grade field trip called “Animals of Acadia.” The big, yellow buses started at The Precipice – the nesting habitat of peregrine falcons. On a good day, we could see their elegant forms darting gracefully in front of a craggy cliff. It took me a while to understand how peregrines and beavers fit into the same program – the only time beavers look elegant is after they’ve been skinned and felted into hat – but I came to appreciate their parallel histories of exploitation and steep decline, as well as protection and recovery.
One of the goals of the Acadia field trip was to teach the students about animal adaptations. While you can hardly find two animals that are more different, beavers and peregrines also share the reputation of being extremely well adapted to their particular lifestyles.
As the beam from my headlamp followed the beaver on his journey, his eye sparkled back at me just above the surface of the silver lake. I paused to admire the effectiveness of his oddly-shaped head. Just that morning I had pulled a skull out of the education tub to show some second graders how the beaver’s eyes, ears, and nose are all crowded toward the top of his head. This allows the beaver to hear danger, see where he’s going, and breathe continuously, even while having most of his head and body stealthily submerged.
I also enjoyed watching the kids react to the news that beavers have a third, translucent, eyelid that closes sideways and acts like swim goggles. They were jealous! I could see their little minds churn as they imagined what they could do in their favorite lake with built-in goggles. I wouldn’t mind having the beaver’s ear, nose, and throat flaps to keep water out, too.
The beaver’s rust-colored teeth also caught the students’ attention and spurred questions – which is one reason I love having access to dead animal parts for teaching. The orange surface isn’t due to poor dental hygiene. (Although, maybe saying that would encourage kids to brush their teeth more.) The orange color comes from iron in the enamel which strengthens the surface and buffers the teeth against acid that could cause tooth decay. The iron works even better than fluoride!
Behind the orange surface, the beaver’s front teeth are made of softer, white dentin. As the beaver gnaws down trees, the dentin wears away at an angle behind the enamel, resulting in self-sharpening points – an innovation that would be welcome in my knife drawer!

When I teach kindergarteners about beavers, we don’t go into those details. We stick to the theme of “exploring nature with our senses,” which means taking turns touching a beaver pelt. They get to experience the soft, dense underfur that provides insulation, and the long, glossy guard hairs that help keep the beaver waterproof. At one of my favorite schools, a little class clown sprawled out on the fur, then grabbed a corner and rolled around like the beaver hide was attacking him. His classmates ignored what must have been a familiar scene, but I had to work hard not to laugh.
The kids also pass around a cloth bag concealing a beaver tail. Flip-flop, shoe, and flyswatter are some of their guesses about the mystery object. About once a year, one outdoorsy kid will recognize the tail right away. Inevitably, the kids are curious, and want to touch the tail again. When I ask them how the beaver uses its tail, inevitably I have to clarify that only cartoon beavers use their tails to pat mud on their lodge. Real beavers use their tails to swim, store fat for the winter, as a kick-stand while cutting trees, and of course, for slapping the water in alarm.
Before I even finished the story of my nocturnal beaver encounter, six little hands shot in the air, eager to share their beaver encounters, too. The kids’ enthusiasm was a bit like my flashlight – adding a bit of a sparkle to an otherwise dowdy creature.

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new exhibit: “Lake Alive!” opened May 1, 2015, and will remain open until March 2016.

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com.