Mother Nature Is Trying to Kill You (23 page)

I’ve seen pallid bats on several occasions, mostly in the cracks under bridges in Texas and California, but my most wonderful memories of pallid bats come from a night with Shelby at a campground in Texas.

A few years after I started dating Shelby, we took a road trip around Texas with my mom, to see some bats and caves. My mom’s always been supportive of my weird fascination with bats, and one year she told me she wanted to see some bats firsthand. Texas was an obvious destination, since it has those spectacular bat caves we discussed in the chapter on gluttony, filled with so many Mexican free-tailed bats that it takes up to four hours for all
of them to come out each night. My favorite of them is the Eckert James River Bat Cave Preserve near Mason, so my mom and Shelby and I started there.

Once we’d seen that bat cave, I told them about a bridge four hours away, under which pallid bats had been seen about ten years earlier. On the off chance they might still be there, we decided to make the drive.

Unfortunately, the bats weren’t under the bridge (although we did find a complete cougar skeleton lying on its side there, which was exciting). That afternoon, we drove to the nearby campground at Balmorhea State Park, set up our tents, and had dinner. As the sun set, my mom went to sleep in her tent, and Shelby and I went out for a late-evening walk to look for wildlife. I love southern Texas because you can see all kinds of things there, from tarantulas to giant walking sticks, that are absolutely nothing like the animals I grew up with in Edmonton. That night we even lucked into seeing a scorpion. What with the cougar skeleton, the scorpion, and the general beauty of the area, we’d had about as good a day as a couple of biologists could possibly have. It was about to get way, way better, though.

As it got darker, Shelby and I kept walking until it got dark, eventually arriving at a playground on the edge of the campground, where we stopped to sit down in the sand. Then, using a trick my PhD advisor had once taught me (he had done part of his own PhD on pallid bats), I scratched the sand with my finger. Apparently, that makes a sound very similar to the sound a scorpion makes when it walks in the sand, and to a pallid bat, that’s practically a dinner bell.

Almost instantly, there was a bat hovering right in front of my face.

I couldn’t believe it.

I couldn’t turn on my headlamp to look at it, even though it was almost pitch-black out, because I knew that would probably scare it off, so I let my eyes adjust to the darkness and tried to make out its shape. I could clearly hear its flapping wings but could barely see it. It hovered for several seconds, but then, as suddenly as it had appeared, it flew off.

Immediately, I tried again, and sure enough, another bat showed up. At first, Shelby and I whispered back and forth with the requisite “Oh my
God
!” and “Can you believe this is really happening?” but before long we just went silent to enjoy the experience together. We sat together at first, but then lay down in the sand, holding hands, looking up at the stars, and calling pallid bats in with our fingertips. I don’t know whether just one bat found us interesting or if we fooled an entire colony, one after another, into believing there were scorpions in the sand. But whatever the number of bats we saw, it was a perfect night.

In fact, that dark night epitomizes what I love most about nature. There I was, outside, with the woman I love, watching silhouettes of my favorite creatures against a backdrop of stars. On the one hand it was totally peaceful—the silence, the cooling wind, the fresh air—but on the other hand I felt defenseless and vulnerable, lying on my back in darkness surrounded by insects, scorpions, and, for all I knew, more cougars. But the way those elements took me out of my comfort zone is a big part of what made that night so special. To me those scary animals are what bring nature to life. Knowing I’m surrounded by animals that could hurt me reminds me that nature’s not weak or passive. It reminds me to respect the natural world.

Unlike many experiences in nature I’ve had alone, that night
was also a special one for Shelby and me as a couple. It was wonderful for both of us to be able to share an experience like that, with the hostility of the creatures in that environment juxtaposed with the kind of relationship the two of us had built. Against a backdrop of wrath, the caring, loving, and patient affection Shelby and I share was even more apparent.

From an aesthetic perspective, nature’s wrath is a big part of what I think makes it so beautiful, but my poetic thoughts don’t mean crap to any of the animals out there. On a day-to-day basis, that wrath exists because it can spell success for the animals that wield it. One Texas resident, the venomous fire ant, is a perfect example.
^XI
I weigh around 50 million times what a two-milligram fire ant does, but a fire ant can hold its own against me just fine. The bite of a single individual can leave a welt on my skin that lasts for days, but that’s not what scares me about them. It’s the fact that a person never gets
one
fire ant bite. Fire ants, like most ants, are successful because they deliver their wrath en masse.

When you accidentally stand on top of a fire ant colony in your sandals, they come at you right away, but they don’t bite you in those first moments. Instead, they invade enemy territory—crawling up your legs by the hundreds. Because of their small size, they’re barely noticeable. But you notice them soon enough, because eventually one of those ants does bite you, and in so doing, releases a smelly chemical into the air that gives everyone else the signal to bite too. As nearby ants bite, they release more of that
same stinky chemical, causing others to bite, and so on. Not only that, each ant can bite multiple times. As a result, one minute you feel nothing, and then suddenly every square inch of your legs burns at once. If they’ve gotten far enough up your clothes, you’ll need to drop your pants immediately to get the ants out of there. Despite how socially awkward that might be, you really have no choice.
^XII

Once the ants are gone, the bites are just a little itchy and annoying, but over the next few days they grow, until a day or two later the pus-filled welts on your skin are even bigger than the ants that left them.

Fire ants suck.

Ant bites are painful, partly because of an acid that ants have in their venom. It’s called formic acid, after the Latin word for ant,
formica
. Working as teams, injecting their enemies with formic acid, ants have flourished around the world. There are more than 12,000 ant species out there,
^XIII
and the number of individual ants walking around on Earth is almost unfathomable. Biologists have famously estimated that if you took every single land animal out of the Amazon rainforest and put them all on a scale at the same time, about one-third of that weight would be made up of ants and termites.
^XIV

One of the Amazonian ant species that would be on that scale
is called the bullet ant. I don’t know if it got that name because it’s an inch long, roughly the size of a bullet, or because when it stings you it feels like being shot. Either way, when Shelby was doing fieldwork for her PhD in the Brazilian Amazon, the locals often warned her about bullet ants. They had a different name for them, though:
vinte e quatro
, or “twenty-four”—apparently the number of hours for which you can expect to be in searing pain after being stung by one.

There’s an indigenous tribe in the Amazon, called the Sateré-Mawé, that uses bullet ants in a rite of passage for its men. During a ceremony called the
tucandeira
ant ritual, the young man puts his hands into a pair of ceremonial gloves that look like giant oven mitts woven out of leaves. Each glove is filled with up to three hundred bullet ants, and the man must leave his hands in there for several minutes while he does a ritual dance. The thing with bullet ants is that the pain gets steadily worse after the stinging and climaxes several hours later, so the ritual goes on for hours after the men take their hands back out of the gloves. This ritual starts for men around the age of twelve and may be repeated twenty-five times or more in a man’s life.
^XV

The sting of the bullet ant has a pretty solid reputation as the most painful of any insect, but of course the only way you could really know that would be to go out and get stung by as many different kinds of insects as possible. And if you think no one would ever do something like that, you clearly haven’t spent enough time with entomologists.

Justin Schmidt studies ants and their close relatives, the
wasps and bees. Collectively, these three groups of insects are called hymenopterans, and if there’s one thing ants, wasps, and bees are famous for as a group, it’s that they sting. In the course of studying these insects, Dr. Schmidt has been stung many times, but instead of just swearing loudly about it, he’s recorded what each of those stings felt like. The result of his work is the Schmidt Pain Index.

The Schmidt Pain Index is a list of scores for different hymenopteran stings, describing how painful they are. It goes from one to four, with four being the most painful. The best part about the Schmidt Pain Index is that some of the stings are described almost the way one might describe a wine. For example, the sweat bee, with a score of one, is “light, ephemeral, almost fruity. A tiny spark has singed a single hair on your arm.” The bull’s horn acacia ant, which you may recall from the chapter on gluttony, scores a two and gives “a rare, piercing, elevated sort of pain. Someone has fired a staple into your cheek.” There are a few hymenopterans with a score of four, and the bullet ant is one of them, described as “Pure, intense, brilliant pain. Like walking over flaming charcoal with a 3-inch nail in your heel.”
^XVI

In interviews about his list, Schmidt has said that the pain of a bullet ant is the worst of them all, but although the Schmidt Pain Index contains an impressive 78 species, it falls slightly short of covering all 117,000 species of hymenopterans out there.
¹⁸
So while the bullet ant may well have the most painful bite of any insect, there’s still clearly a world of pain available to any other entomologists looking to have an index named after them. A good
starting point might be the enormous, one-and-a-half-inch-long ant
Dinoponera gigantea
of Brazil, which is not part of the Schmidt list, and whose sting might be even more painful than that of the bullet ant. A medical report from 2005 of a sixty-four-year-old man stung by a
Dinoponera
ant describes incredible pain (more intense than passing a kidney stone, he said), cold sweating and nausea, a vomiting episode, and an irregular heartbeat. Three hours later, the man passed stool with a large amount of blood in it, having not had any such problems prior to his sting. His intense pain only started to decrease eight hours after he was stung.
¹⁹
I’m thinking this ant might give a bullet ant a run for its money (but I’m not going to be the person who signs up to compare them).

As impressive as it is that an ant can make you poop blood, there aren’t any hymenopterans with a venom so powerful that a single sting can be lethal. Some people have allergies to fire ants or honeybees, so complications from those stings can be deadly, but if you don’t count allergic reactions, or swarms of hymenopterans attacking together, the stings of bees, ants, and wasps are mostly just painful. In fact, adding up the jellies, the cone snails, the spiders, the scorpions, and the hymenopterans, you don’t get anywhere close to the number of human deaths that you get from the top killers. None of the venomous creatures I’ve listed in this chapter so far has even made a slight dent in human populations. That changes, though, when you consider the deadliest of all the venomous animals out there: the snakes.

Of the 3,400 or so snake species in the world, only a few hundred are venomous, but a large number of those venomous snakes eat mammals.
²⁰
Even though we’re not the mammals that those venomous snakes feed upon, we’re similar enough to the mammals they do eat that snake venoms are often deadly to us
too. Combine that with the fact that snakes hide well and strike quickly, and snakes start to look like the poster creatures for this book.

It’s kind of shocking how many people get killed by venomous snakes. Most deaths happen in poor countries, where people work in agricultural fields without proper footwear, far from sufficient medical infrastructure. Exact numbers are hard to come by because records in those regions are not as well kept as in other parts of the world. To give you some idea of numbers, though, the country of Bangladesh alone suffers roughly 6,000 deaths per year because of snake bites. Worldwide, the estimate ranges anywhere from 20,000 to 125,000 deaths per year.
²¹

As with other venomous animals, different kinds of snake venoms work in different ways, and any given snake’s venom is a cocktail of different kinds of molecules.

Some snake venoms simply kill the cells with which they come in contact, causing swelling and blister formation and ultimately causing the flesh to turn black and die. Imagine one whole side of your leg, from your ankle to your hip, with the skin and underlying flesh eaten away chemically. That’s what a bite from a spitting cobra can do. And just in case that doesn’t hurt enough, the bite also contains chemicals that make your body feel intense pain at the site of the injury.
²²

Other snake venoms affect the cardiovascular system. Some cause a sudden drop in blood pressure, while others do exactly the reverse, squeezing the arteries around the heart until it can’t beat properly for lack of oxygen. Others affect the blood itself. They might prevent blood from clotting, as is the case with the venom of the copperhead, or they might make the blood inside you clot up into blood Jell-O, as does the venom of the fer-de-lance.
²³

Then there are the snake venoms that are neurotoxins. A few pages ago, when we were talking about spider venoms, I mentioned chemicals in your body called neurotransmitters, which your neurons use to send information to other neurons. There are two different ways a snake neurotoxin can screw that process up, but some of them are permanent and others are temporary. This difference is pretty simple: it depends on whether the neurotoxin affects the neurons sending the neurotransmitters or the neurons receiving them.
²⁴