Bedbugs, Deadites, and the Problem of Induction

“What? What? No. No, it can’t be! You’re coming back to life? No, I killed you. I killed you all! You’re dead!” – Ash, Evil Dead: the Musical

Early in the morning of the first day of Reading Week, I woke up to find something moving around on my sheets. A  devilish something that looked like a cross between a tiny cockroack and those crawly things you used to poke in grade school to make them curl up into armadillo balls. Its name? Bedbug.

But its name might as well be legion, for all the good referencing once-popular movies will do. Bedbugs, you see, are like Pokemon: you gotta catch ’em all. The critters are devious little things that can hide in any space you can fit the edge of a credit card; their larvae are tiny; and their eggs are practically invisible to the naked eye. Worse, they can survive dormant without food for up to a year. They will find you in a new room or hitch a ride to your new house if you try to move or escape to a friend’s. Although they prefer fabrics and wood, they will hide in almost anything. They can survive being squished. Even professional exterminators can have trouble with them.

In fact, bedbugs are the zombies of the insect world. Like the Evil Dead, they quickly spread in uncontrollable ways. Like the Evil Dead, they inspire otherwise rational people to stay up all night clutching a high-powered flashlight. And, like the Evil Dead, you can never really be sure that they’re gone.

Everyone knows that the minute our hero Ash breathes a sigh of relief because the last shambling corpse is chainsawed into bits, that’s just the sign that ten more are about to spring up out of the woodwork. That’s how horror movies work: whenever you think you’ve seen the end of the evil, you’re being set up for a terrifying reversal. If you were a character in a horror flick – lacking clues the audience can count on, like knowing the length of the film – you’d never be able to relax.

In other words, you can tell I like to think things over a bit too much because my reaction to being beseiged by bedbugs (or zombies) is: when is it reasonable to assume they’re gone for good*?

During a quiet moment with his boomstick, Ash’s thought processes (if he has them) go something like this:
1) I haven’t seen any sign of the Evil Dead in X amount of time.
2) It seems Y likely that, if there were Evil Dead around, I’d be aware of their presence within Z amount of time.
The million-dollar question is, what’s the relationship between X, Y, and Z that justifies Ash going on to conclude:
3) The Evil Dead are gone for good.

In some ways, this resembles one of the traditional problems of induction – that of the black swan. Sort of rearranged and over-simply put**, how many white swans does one have to observe to be justified in concluding “all swans are white”? After all, it takes just a single sighting of a black swan to prove that statement wrong. Even if you observe a googolplex of swans that put ivory to shame, if the next one to cross your path is Australian, you’re just as wrong as the guy next to you who’d seen one Trumpeter swan in his entire life yet still shared your belief that all swans are white.

Luckily for philosophers, there’s no easy answer to this question, despite it affecting pretty much all attempts to gather information about the world we live in.

However, there’s one important way in which swans differ from zombies and bedbugs (incidentally, this shows how philosophers differ from everyone else, as most ordinary people would agree that there are in fact numerous salient features that swans do not share with zombies and bedbugs, not the least of which being the whole consuming-your-brains-and/or-blood thing): in the swan example, we’re talking about discrete instances of observation. With bedbugs and zombies, we’re talking about continuous failure to observe.

Suppose I temporarily transplant Ash into a nature documentary. If I then ask him, “How many white swans did you observe?”, he can answer me with a single whole number. However, whether or not I teleport Ash back to his Evil Dead-infested cabin in the woods, it makes no sense to ask, “How many zombies did you not observe?” Not observing is a different animal from observing. Generally, unless we’ve been known to hallucinate or there are other extenuating circumstances, observing something means that thing is present. However, not observing something doesn’t mean that thing isn’t present – it just means that we’ve failed to observe it. (Consider, for instance, the formidable singing talents of Michigan J. Frog.)

The circumstances of not observing also matter in a way that those of observing don’t (necessarily). If you see a white swan, you’ve seen it regardless of whether you just happened to glance over and spot it or you’ve spent the last month following its tracks, spoor, etc. But if you don’t see a zombie, it’s going to make a difference to our state of knowledge whether you’ve scoured every inch of the cabin and the surrounding woods for any sign of the undead or you’ve sat on your bed wearing a blindfold and earplugs.

You might want to argue here: isn’t the white swan thing the same if, instead of characterizing it as “how many white swans we see”, we characterize it as “how long we go without seeing a non-white swan”? While this is true, I think the context of swans vs. that of zombies and bedbugs gives us good reason to think of the situations differently. In the first case, we don’t know that non-white swans exist. There may be no such thing. In the second, we do know that zombies and bedbugs exist and that they are capable of infesting our mattresses and/or shambling after us moaning, “Braaaiiiiins!” After all, we’ve already experienced it.

Anyway, judging by some of the experiences posted online about bedbugs (and by pretty much every horror film ever), some people believe it’s never reasonable to finally feel secure laying down the shotgun. There’s always a non-zero possibility that the horrible creatures are still there, biding their time and waiting.

But practically speaking, you can’t live the rest of your life in fear. At some point, most people are going to figure, okay, the nightmare is over, and I’d better start living my ordinary life now again. But when is that point? Given a particular degree of belief in the salience of zombies or bedbugs, is there a specific time after which it’s okay to stop worrying? Does that mean one second before the time passes, it’s not reasonable to feel safe, but an instant later it is?

You’ve probably noticed by now that the scrolly-bar is nearing the bottom of the screen***, so it’s safe to assume I’m not going to provide a definitive answer to this. However, I’ve just as obviously got to adopt a pragmatic, if not necessarily philosophically sound, solution. If I give in to despair now, the bedbugs win. So maybe, rather than simply demand that I am provided with good reason to believe that there are no bedbugs whatsoever, I can adjust the perceived utility of bedbug-related incidents: in other words, sure, I could maybe scour every square centimetre of every soft surface in my room with a microscope or call in special sniffer dogs, but I just don’t care that much. Furthermore, I have to be pretty sure the bedbugs aren’t gone before it becomes more worthwhile to me to sit and fret about them than it does to forget about them. So even if I have no good reason to presume my residence is and will remain 100% bedbug-free, it doesn’t matter, because I still have good reason to act as though I believe it. *backslash cheap way out*

Oh, and incidentally? Don’t worry: both the building guy and the exterminator say it’s the lightest infestation they’ve ever seen, and I’m lucky to have caught it so early. They’re all but gone now, and I should be doubly secure after a second room-spraying this Wednesday. And, as for zombies, well, horror movies are fun and all, but everyone knows dead people don’t come back to islaujkdnvml,c

BRAIIIIIINSSSS….

* I am sure there’s a large body of academic literature on this subject, although maybe not making specific reference to either bedbugs or zombies. However, I choose to put my fingers in my ears and ignore it.

** Please don’t kill me, philosophers.

*** Unless you have, like, a giant computer screen.