We had a little discord in the naturalist department a while back, something I suppose was bound to happen eventually. Our staff is small, and our work space is limited. It was inevitable that, one day, someone would move somebody else’s stuff around and trigger some resentment.
Thankfully, the conflict was short-lived. Even better, it’s safe to say that we all learned something as a result. Best of all, nobody got bit or had to endure the burning itch of urticating hairs.
I suppose I should explain. The issue centered around Miss Spider, the Chilean rose tarantula that lives in the Nature Room at the Pottawatomie Community Center.
For the past nine years, she and I have had what I consider to be a good working relationship. I give her crickets and handle her gently, and she doesn’t bite or flick her urticating, or irritating, hairs on me.
However, one area where we’ve never been in harmony is the state of her terrarium. A creature of habit, Miss Spider would prefer that everything stay the same all the time. Moist sponge in one corner, log in the center, deer pelvis for hiding in the back. Oh, and silky web spun across everything, to facilitate the hunting and capture of her cricket prey.
But when you eat insects for a living, sooner or later, things are going to get messy. And that’s the point we’d reached a few weeks ago. Strewn with cricket carcasses and assorted other spider debris, her enclosure had begun to look unkempt. It was time to tidy things up.
The actual cleaning process was pretty painless. I moved Miss Spider to a plastic “Kritter Keeper” and put her on a countertop well away from the proceedings. After emptying the cage, I scrubbed every nook and cranny, then put in fresh substrate and replaced her sparse furnishings—taking care, I thought, to put everything back exactly as I found it.
Well, needless to say, Miss Spider begged to differ. Placing just one of her two pedipalps (the “feelers” near a spider’s mouth) into the new substrate was enough to let her know that her home environment had been irreversibly altered. She immediately crawled back into the Kritter Keeper, and no amount of coaxing could convince her to come out.
Running short on time, I finally reached in, picked her up, and put her on her old, familiar log. But, alas, its surface had been scrubbed clean. It was no more familiar to her spidey senses than the alien coconut fiber I’d lined her cage with. Within minutes, she’d crawled off the log and up onto the glass side of the terrarium, where she stayed.
And stayed and stayed.
Her hours on the glass turned into days, then weeks. In fact, she stayed on the glass so long, we curious naturalists had to poke her, to make sure she hadn’t up and died. It also prompted us to investigate further, so we could have the proper answer to the question so many folks were asking: What makes her stick like that?
It turns out tarantulas, much like certain species of spiders in your own home, have tiny clumps of even tinier hairs on the bottoms of their feet. Called scopulae, these tufts contain thousands of microscopic, branched hairs called setules. One spider foot can contain, by some estimates, 78,000 setules, and most spiders, if they’re lucky, possess eight feet. What that adds up to is more than 600,000 individual points of contact per spider—a whole lot of staying power, even on apparently smooth surfaces like glass. As long as nothing disturbed the molecular attraction between Miss Spider’s setules and the small imperfections on the glass, she could hang there indefinitely.
Luckily, that wasn’t the case. She eventually came down, then proceeded to spend another two or three weeks sitting atop her deer pelvis before finally coating her new substrate with silk—the ultimate sign of spider acceptance. Safely ensconced in her newly reclaimed territory, Miss Spider can now get back to the job she was “hired” for—namely sitting quietly and displaying, as only she can, her quintessential spidery traits.
The next time you see a spider skittering along your window, wall or ceiling, remember the story of Miss Spider. Even if arachnids aren’t really your thing, stifle the urge to shriek, squelch the urge to squish, and take just a moment to marvel at the gravity-defying might of those 624,000 setules.
Pam Otto is the manager of nature programs and interpretive services for the St. Charles Park District. She can be reached at potto@stcparks.org or 630-513-4346.