I was excited to go home to the Twin Cities last weekend to join my family at the Minnesota State Fair. Starting out early in the morning, we found breakfast at the mini doughnut stand and wondered what to do next. My eye was soon caught by a tortoise outside of “Monty’s Traveling Reptile Show.” I always thought this building was a little tacky, with signs worthy of a peculiar circus, and had never been inside. I was surprised when my mom said, “Let’s go in, you’ll love it!”
The atmosphere inside was not the circus I was expecting. Instead, a variety of reptiles lay in individual terrariums with educational signs about each. The number of reptiles represented from around the world was stunning. As I stepped away from the diamondback rattlesnake display (grateful that I live in a place with so few deadly animals), I saw a peaceful Black-throated Monitor lizard snoozing against the glass. There was a clear view of a gaping hole in the side of his head.
I knew that snakes don’t have external ears, so what could that hole be? It turns out that most reptiles like lizards, crocodiles, and turtles, do have external ears. This lizard’s tympanic membrane, or eardrum, was clearly visible and capable of picking up sound waves through the air.
After a full day at the Fair, I was relieved to return to the quiet town of Cable and to care for my own reptiles. I had to admire Digger’s smooth head which lacked a hole for his ear. His ear structure (hidden behind a layer of scales) is capable of hearing sound waves through the air but is better equipped to sense vibrations transmitted through the ground into his jawbone. Even though he didn’t respond, I’m sure he heard my excited, “Hello, Digger!” when I returned.