In a fit of inspiration that results in either elaborate new home decor or a child, my wife recently replaced the two-decade-old biohazard-level carpet in our living room with hardwood floors. My contribution was nodding compliantly and helpfully noting that every piece of dust, dog dander and loosed human skin that used to sink into the old carpet was now plainly visible, in great wide swaths, a billion little grey dots on deep brown.

And that’s why we got a Roomba.

Or, rather, that’s the excuse I used to get a Roomba. I mean, I could replace the previous paragraph with “And that’s why I vacuum every day” or “And that’s why we continue to live in filth” but, come on, the cost of the Roomba was some fractional percentage of what we blew on the floor and it’s a freakin’ robot. In my house. Doing my unquestioned bidding, as long as my bidding involves vacuuming.

Which, somewhat disturbingly, it often does.

The Roomba works astonishingly well. It doesn’t do a human-good job, but for day-to-day cleaning — picking up whatever the combination of kids, dogs and 1960’s central air produces — it’s perfect. It’s too loud to run automatically in the middle of the night — “There’s someone in the house! And they’re dust-busting!” — but if you let it go while you’re out on errands, you came back to a cleaner house. Which is a pretty great trick.

And so I love the Roomba… mostly. I mean, it’s great and all, but… Geez. How do I say this? It… It sort of creeps me out. And not just in the way that something that cleans without complaining creeps me out.

This turns out to be not unfamiliar territory for robots.

“The Uncanny Valley” is shorthand for the revulsion that human beings feel when watching Robert Zemeckis movies. Or, rather, for when you’re watching computer animation or robots that come close to looking like humans, without actually getting all the way there. The jerky movements. The dead eyes. The inevitable malfunction and ensuing horrific slaughter. We love our robots R2-D2 adorable, not as walking corpses.

And, yes, OK, the Roomba doesn’t look anything like a person. But it does perform the function of one, and in performing that function, it enters an Uncanny Valley of Behavior.

The Roomba has a handful of different methods for covering a room while it vacuums. And, just by looking at the result, they work great. However the Roomba programmers picked these methods — and I can’t imagine that a group of nerds putting together a vacuum cleaning robot didn’t try every one they could think of — it all appears effective as the dickens.

But watching the Roomba run its routines is frustrating, in a way that watching a human vacuum isn’t. Or, rather, the way I presume that watching a human isn’t, because the only human I ever see vacuuming is me, in a mirror, and that’s incredibly frustrating.

Human beings, when they come across a patch of dirt — and, no, I don’t think that “patch” is over-doing it, not in my house — work the vacuum back and forth until all the dirt is gone. You’re there, you finish it. I don’t care how much you love your grid pattern, OCD Boy, you’re just not going to move on until the immediate area is clean.

But the Roomba will merrily roll right through the bad spot. Zoom. It comes back, eventually, following whatever commands its tiny little brain is giving it, and the floor ultimately gets clean. But watching it not behave like a human — and, yes, I do spend far more time watching the Roomba vacuum than I ever spent vacuuming myself — is… disconcerting.

It makes sense that the Roomba behaves differently than a person — it’s got a different design, with different strengths and weaknesses. But as robots make their way out of factories and into contact with the general population, there’s bound to be a disconnect, a brainstem-driven objection to how they go about doing what they do. They won’t look like humans — it makes no sense to design specialized robots to mimic the awkward shape of people — but they will be doing the work of humans, and doing it in ways that are alien to us, ways that that better suit their dumb, slow, nothing-but-time constraints. Ways that are going to seem creepy as hell.

With the rise of the robots, our world is going to be turned into an endless Uncanny Valley of Behavior. No matter how effective the machines are, some distant memory will crawl out of our lizard brain and insist that they’re doing it wrong. And we’ll squirm and fidget and ultimately get used to it and let the robots go about their business.

Because the alternative is doing the vacuuming ourselves, and there’s no way in hell I’m going back to that.