The word "vermin" come from the Latin word for "worm". Few people distinguish between worms and maggots, so the habit of calling maggots "worms" led to the general habit of calling disgusting creepy-crawlies in general "vermin". This, then underlies the grossly delicious children's rhyme,
The worms crawl in, the worms crawl out,NB: This comes in a lot of varieties; the one here is the one I learned, and one of two versions found in the book I'm introducing.
The worms play Pinochle on your snout.
Your eyes fall in, your teeth fall out,
Your brain turns into old sauerkraut.
I've always been one for whom fascination usually overcomes disgust when it comes to "critters". Just today, the first few Autumn ants showed up in our kitchen. As I was disposing of them, I began to marvel at the intricacy of their bodies: not just six legs, three body segments and a dozen sections to each antenna, but the hundreds of tiny muscles, with a nerve fiber to each one, in a body no more than three or four millimeters long. That's a bunch of working parts per cubic millimeter! (And lest you think larger animals are slouches in this regard, every hair on a mammal's body, including yours, is manipulated by six tiny muscles)
In Spineless Wonders: Strange Tales From the Invertebrate World by Richard Conniff, the focus is not so much the insides of the creatures' bodies, but on their behaviors. The author grabs our attention at the outset with his introduction, "The Joy of Formication". Check that "M" there. "Formica" is the Latin word for "ant", and formication is the sensation of having ants crawling about on your skin. Not so joyful after all!
The book treats, in order, flies, leeches, fire ants, squid, dragonflies (and damselflies), tarantulas, fleas, a few kinds of beetle, earthworms, mosquitoes (the most dangerous insects), moths, and slime eels. The last mentioned are the least known, so they deserve an early mention. Also known as hagfish, they are the ultimate clean-up squad of the ocean. Anything dead that reaches the ocean floor, at nearly any depth, will soon be devoured entire by a wriggling mass of pink, eely, slimy hagfish. And they really are the slimiest creature ever. I think of them as "non-vegetable Okra". But they aren't really eels, because they don't have a skeleton, though they do have a skull of sorts. They are Nature's first, halfway step towards vertebrates, and have managed to hang around for several hundred million years, with only incremental changes if any.
The rest of the critters mentioned are true invertebrates, though squids and cuttlefish do have a single internal bone that takes on a few of the spine's functions. The next time you look in the cage of a parrot of parakeet, look at the flattened, white, oval "beak scratcher". It came from a cuttlefish.
The creature that seems to evoke the greatest fear and loathing, though, is the tarantula. It must be that, in the dim past, maybe when our ancestors weighed just a few pounds, and dragonflies were the size of robins, there were some really big spiders, which made a habit of dining on young primates. But if you are in Texas or Oklahoma or a nearby state in "spider migration season" (early Fall), and you see a tarantula crossing the road, resist the impulse to make a spider pancake. Instead, pity the poor, male tarantula; he is just one year old. He has just a few days to find a female who is willing to mate. When he finds her, and gets her "in the mood", he holds onto her fangs while they mate, then if he is lucky, he can take advantage of a moment of calm to make his escape. She, who may be eight or ten years old, is quite likely to grab him and chow down, to get extra protein to make lots and lots of eggs.
Well, the tarantula is just one kind of spider (there are a few hundred species of them). The most numerous inhabitants of your backyard are not spiders, but their prey, either ants or moths. There may be twenty to fifty species of ant in your yard. There are probably at least four hundred species of moth, if you live in a temperate area, and many, many more in tropical realms.
Most moths are tiny, gray fluttering things we seldom see. But they are pollinators second in importance only to honeybees (maybe!). They are also food for every kind of predator, of every size. In Yellowstone, a seasonal moth is an important part of the diet of Grizzly bears! And did you ever see a ballooning spider land, and wonder what a spider with a body somewhat smaller than a pinhead will find to eat? Rest assured, there are a dozen kinds of moth that are smaller yet. At the other end of the scale, the Atlas moth is about twice the size of the largest butterfly; its wings will hide most dinner plates.
As I mentioned, mosquitoes are the most dangerous of vermin. Malaria still kills three million people yearly, the most deadly single disease. Many other diseases, some also deadly such as yellow fever or encephalitis, are carried and inserted into us by these living hypodermics. Yet we are not nearly so fearful of mosquitoes as we are of a spider of equal size. We ought to be.
This book is of a genre I call "survey", and I can read them without end. There are always more neat things to know about nearly anything.