“What’s this?” my wife said.

She held up a shiny, speckled red ball about the size of an acorn. Me being the amateur naturalist and science fictionist in the house, and everybody else being merely curious, she expected I’d have an answer, or at least a weird guess.

“I have no idea,” I said. “Where did you get it?”

“Jack found it in the grass by the Shed.”

She handed it to me. It was smooth and looked like some kind of fruit or nut, although it had no apparent stem end. I went outside to look around.

Around the Shed (which outside looks like a run-down toolshed, but inside is a library with wall-to-wall books) are fir, pine, beech, oak, maple, hemlock and cedar trees, none of which drops small round fruits. That I know of. The Shed is attached to the garage, on the other side of which are a red-osier dogwood and the carcass of an elm tree that died so suddenly you’d swear it had a heart attack. But they don’t grow acorn-sized fruit either. In 14 years here in Troy, we’d never seen this thing before.

I searched the ground among the acorns. Soon I spotted one of the red fruits and picked it up. Weird. Were they a rare type of acorn? Or maybe they were pods of uncertain origin that would send out tendrils in the night, fasten themselves to our sleeping faces, and clone us into expressionless human-alien hybrids that would dispose of our withered bodies in Wednesday’s trash.

Maybe not.

Back in the kitchen I got out the tree and flower books and paged through, but found nothing resembling the pods, as we were now calling them. I gave up for the time being and left them on the kitchen table, hoping the tendrils would not be long enough to reach the bedroom.

The next evening, the pods were noticeably drying out. Two days later they were downright shriveled, like oversized raisins. When I went back out to the Shed, where the science fiction novels actually are housed – out of range of those who are merely curious – I picked up five or six more pods and rechecked the tree and flower books – which are kept in the house itself – but still found no resemblances.

Next morning I brought a fresh, shiny one to the office. None of the other amateur botanists could identify it either. When a day later the pod was shriveling, one of my colleagues who knows a lot more biology than I decided to solve the problem before baby creatures with prehistoric teeth started erupting from our chest cavities while we worked.

The truth, as often happens, was one of those disturbing natural phenomena that generate, rather than result from, science fiction. It was not a fruit. It was a growth.

On a table in the office library, we cut the pod open. Inside was a white worm, or more accurately, a larva. The larva, we eventually discovered, was that of a gall wasp, a tiny nonstinging flying insect. The gall wasp laid its egg in an oak leaf and left a chemical that induced the tree to grow this fleshy pod, or gall, around the egg. The larva grew inside the gall and would feed on it. Some galls grow right inside the acorn, and some, like the ones around the Shed, grow outside and fall out of the trees.

When nature gets an idea, watch out. At least 200 species of creatures use oak trees to make galls to nurture their young. Some birds and squirrels know they’re there, and eat them.

Sometimes it seems uncomfortably like nature has an actual imagination. Nothing seems too weird for it, or too far off the beaten track – unlike most of us who don’t stray too far from the house, lest the monsters make us mad.

Dana Wilde may be reached at naturalist@dwildepress.net.