I don't remember what drew my eye to that little rivulet at my feet. Maybe it was the sharp contrast between unusually dark water and lingering snow. Maybe it was the unnatural look of the flow, murky, opaque, oddly alive. I crouched down and looked closer.

It was early spring, some thirty years ago, in the woods north of my home in Oswego County, New York. The past season's heavy lake-effect snow pack was losing its tenacious grip and giving way, patches melting beneath a warm sun, and I was out walking, just one of those spontaneous, reacquainting walks we take when the land is waking up.

I'm reminded of that day each year when new leaves and black flies compete for attention.

The stream was no more than a hand's width wide, meandering through the forest floor, but it was not water. It was a living current, a ribbon of insects flowing like water itself. Tens, maybe hundreds of thousands of black flies over the course of the minutes I observed, moving past me in a narrow corridor between snow patches. Not emerging from a streambed or pooling from some obvious source, but appearing as though the forest floor itself were exhaling them.

There was no permanent stream uphill, no brook feeding that channel. Just meltwater, flowing down from higher ground, gathering briefly before slipping away under the duff. I watched them, in silent awe. This was emergence. A hatching. A release.

In all my years outdoors, stalking native brook trout and ephemeral wildflowers, walking familiar paths through decades of changing seasons, I have never again witnessed anything like it. A moment as fleeting as the season that birthed it, a glimpse into the hidden rhythms of the forest that most of us, most of the time, pass right by.

We think of black flies as pests, and they certainly are, but that day, they were more than that. They were spring itself: ancient, inevitable, and flowing out of winter's last breath.