Lileks: Things that go screech in the middle of the night

There are three types of strange noises.

1. The ones you can figure out right away. Example: When the lawn sprinkler system kicks on, it bangs the pipes.

"What is that?" Wife asked the first time this happened.

"Probably not a furious elf in the wall forging a magic ring with a sledgehammer," I said. Somehow this is not seen as helpful. Well, it eliminates one possibility; we move on from there. "A very strong elf in a good mood forging an ordinary ring is possible, but less likely. In fact we can probably rule out elves in the wall altogether. Because I just turned on the sprinkler system, that's probably what it is. Noise mystery: solved!"

2. The noises that take awhile to figure out. The other day there was a knocking sound in the garden shed. I thought it might be the mean, little woodpecker that shows up periodically to work on a hole it's been making for weeks, but no, the hole was unoccupied.

The sound was steady but irregular, and for a moment I thought it was my neighbor, who had for some reason decided that this was an excellent opportunity for periodic hammering. But it was coming from the shed. Was the neighbor squatting on the roof of my shed, hammering something? No, he'd ask first.

Ah: A bird had gotten into the shed, and was banging against the window. I hoped it was the woodpecker that had gotten in through the hole but couldn't figure out how to go the other way. "I ought to spackle up the hole and teach you a lesson about drilling holes in people's sheds!" I said. "You know, that sounds like a bird, doesn't it? A Spackle. The Grey Spotted Spackle. Found in the Upper Midwest. Main predator: the roof-squatting Hammering Neighbor."

3. The noises that have no explanation. I stayed in a hotel last week, a 14th-floor room with a commanding view of Fargo. I set about unpacking … and heard a slight faint screech.

Well, new places have different sounds, you get used to them. Perhaps it was an insufficiently greased bellboy's cart. A door that needed a jot of oil. Someone in another room working on his leg-irons with a metal rasp.

Annnnd there it is again. The same duration, the same pitch, the same distant sound. The room abutted the elevator shaft, so I ascribed it to that, and gave it no mind. But I heard it again, and again, and again, and it took on a strange quality of unexplained noises: when I didn't hear it, I waited to hear it. Until I forgot about it, at which point it would happen again.

Eventually I went down to the front desk. The night clerk asked if he could help, and I said I wanted them to be aware that either there was a slight mechanical problem with the ventilation system, a flywheel in need of grease, or there was an elderly asthmatic pterodactyl trapped in the elevator shaft. He mustered the simulacrum of concern you give your guests who just have to complain at 1 a.m., and I went back upstairs.

The next morning, I was checking out, and I took the elevator down with a fellow whose shirt had the crest of the hotel. He asked how my stay had been, and I lauded the room's comfort and style, but noted that someone might want to go to 1403 and sit very still for a while and listen for a peculiar sound.

"Oh yes!" he said. "I saw that in the notes. Something about a pterodactyl."

He had actually come on duty and checked the overnight report to learn that a guest had complained about an extinct avian predecessor. And here was the very fellow himself, complaining about indistinct peeps from a sick dinosaur.

I ran into some departing guests in the parking ramp, and because they were on my floor, I asked them if they'd heard it. They had. They had no idea what it was, either. Sounded like a dentist's drill, they thought.

I almost said, "Maybe the pterodactyl had a cavity." But I thought better of it.