Of slime, bathroom visitors, and biomimicry

Going right onto another topic without finishing the last one (why gender matters when talking about critters) is well, maybe tacky or lazy or both. If you want to know the rest of the story, let me know and I'll finish it.

But right now I'm interested in what I found the morning after the last big rain storm (2 days ago?). I was reaching for a towel in the bathroom when something dark and thin appeared on the pale gray linoleum. "Hmph. Wonder if that's a scrap of my last collage littering the floor? I'll get to it later." My housekeeping can generously be called impulsive, light, and infrequent. I tried to ignore the blackish smudge as I scrubbed my face. Then I realized that it was moving--real slow. "Aw crap."

A 2" mottled gray slug was laboriously slimeing across the very dry linoleum towards my spot by the sink. "Where the heck did that thing come from?" The bathroom sat about 6 feet above the concrete walkway outside, and the small window was jammed shut. The bathroom's plaster wall, mostly held together with a wretched pastiche of left-over latex paint applied by some previous colorblind renter, has no obvious holes to the outside. Then I noticed where the molding was absent along the floor, exposing some dark crevices at the edge of the wall. I suppose it may have come up that way, but that's the basement down there. What could it be eating and why come up to a dry place when they need to stay moist?

A few years ago in Portland I discovered a critter that freaked me out when I first saw it. As I reached over the rim of my bathtub to turn the water on, a 2"-3" a hairy scary scurrying thing was frantically running back and forth along the bottom. Imagine a combination of 5 or 6 big spiders all stuck together, butt to head to butt to head. And moving really really fast like an alien on amphetamines. After the initial shock of seeing my first house centipede, and realizing it was waaay more scared of big ol me, I got to wondering how it made it into the bathtub. Not via the plumbing, a closed system. Research revealed that it was probably trying to reach water and had crawled up into the tub from the bathroom floor, couldn't get out, and freaked. These centipedes roam around in houses searching for silverfish, roaches, and any other small critters they can find.

The slug on the floor made less sense than the centipede in the tub, but there it was, a small Limax. These slugs, that can stretch to over 4" long, are usually found in my moist worm bin about 3 yards away from the back porch steps, competing with the compost worms for delicious rotting vege leftovers in the bin. Which was where I tossed it after picking it's squishy little body up with a tissue--you don't want to get slug slime on your skin, especially the form slugs produce when stressed. The stuff can be so resilient that it stays on your hands through several washings, scrapings, and a lot of cussing. It's so persistent that a couple of decades ago the US Navy was investigating it's gluey strength for use underwater. Apparently it didn't pass muster, but another relative's sticky product did.

Blue mussels, an eminently edible relative of slugs, produce byssal threads. These tough strands anchor the mussels to rocks and and other hard surfaces so the mollusks don't get swept away by waves or low tides. But they have another more exciting function. If a predatory snail crawls up onto a bunch of mussels (remember, they're stuck in one spot), the mussels shoot out byssal strands to entrap the snail. It's all over for the predator, which is now permanently stuck in starvation mode. These threads don't dissolve in sea or fresh water, so they would seem to be ideal for underwater adhesion.

I don't know the results of the Navy's research (should go online to search), but this is one of thousands of natural substances being studied for use in medical, industrial/commercial, architectural, and military arenas. Spider silk, the special connective tissues of sea cucumbers, the venoms of various poisonous marine snails, and the silica skeletons of some sea sponges are a few of the myriad of known substances and structures that have been the basis for the science of biomimicry. Nature really does do it best. Yet another reason to preserve all of those creepy crawlie critters that compel some people to ask: "Well if you can't eat them, what good are they?"

I never did discover how or why the slug made it into the dry bathroom. Go figure.