The Mystery of the Aquarium Pebbles

One day, a year and a half ago, I spotted a couple of aquarium pebbles—those transparent, smooth bits of glass used to anchor aquarium plants—under the bushes near our front porch. I glanced at them as I was going into the house and wondered how they had gotten there. Then I forgot about them until, a few days later, I saw that they were now sitting on the northwest edge of the porch floor. I thought it was odd, but I didn’t touch them. The next day, there were four pebbles neatly aligned on the same place.

When a few days later I found a couple of the pebbles scattered on the dirt, and the rest were gone, I put the whole thing out of my mind. But soon the four pebbles appeared again, all in a row, in their usual spot. I concluded that I was being gaslighted by a creature with OCD.

This went on during spring, summer, and into early fall. The pebbles would get knocked off the porch and then would be put carefully back. But the coup de grâce came in October during the annual invasion of the leaf blowers, who blew my mystery pebbles to kingdom come. Then winter came and I didn’t think about them until spring, after the snow melted. I checked the porch floor and the nearby ground. No pebbles anywhere.

Until today. Today there are four of them again, in the same spot as before. But instead of a row they are arranged in a square. What the heck?

The “pebble spot” is pretty hard to get to, being  practically under the bottom bar of the porch railing, under the eaves, behind a row of tall bushes, and just four or so feet from the front door. So whatever creature is messing with the pebbles and my sanity is dexterous, determined, and brave. A crow comes to mind–they abound in the neighborhood—but the internet is divided between those who maintain that crows love to collect shiny objects and those who insist that they are in fact mortally afraid of them. Besides, I think that, over the many months that this mystery has lasted, I would have noticed a big black bird flapping around between the porch and the bushes.

It could be a raccoon. According to AI, raccoons, like us, are vulnerable to neophilia—the love of new things. Perhaps our neophilic visitor is the same one who disported himself at night in our bird bath last year. But you would think that, having found the treasure, he would take it home to enjoy instead of leaving it on the porch.

Or perhaps it’s a monkey, driven from the tropics by global warming….

I am feeling clueless and pleasantly spooked, and welcome any theories, guesses, or intuitions that you might want to share. But with so much trouble and grief all around us, it is restful to focus on this mini-mystery for a bit. In a way, I hope it never gets solved.

P.S. A naturalist friend has placed a motion-activated camera by the porch. Stay tuned.