Every autumn, between the second week of October and the first week of November, they come. Hundreds of thousands of moths — a species tentatively classified as Manduca meridiana, though its relationship to known sphinx moths is disputed — descend on GLMZ in a migration event that has no historical precedent and no satisfying biological explanation. They arrive from the south, from the direction of the wasteland, in swarms dense enough to trigger atmospheric particle alerts in the lower districts. For three weeks, the air in the Shelf tastes like dust and wings.

Manduca meridiana should not exist in the Great Lakes region. Sphinx moths of the Manduca genus are subtropical and tropical organisms. Their larval host plants do not grow in the Great Lakes Metropolitan Zone. Their thermal tolerance range, based on physiological analysis of captured specimens, should preclude survival in the October temperatures of the upper Midwest. And yet they come, every year, in numbers that suggest a breeding population of millions somewhere to the south — a population that no survey has located, in a landscape that should not support it. They come from somewhere. Nobody knows where.

They are drawn to BCI emissions. This has been confirmed through controlled experiments by the Shelf Naturalist Collective and independently by GLMZ entomologists. Moths exposed to simulated BCI signal fields orient toward the signal source with the same reliability that their ancestors oriented toward light. In the field, this manifests as swarm behavior that concentrates in high-signal-density areas — the moths are thickest where BCI usage is heaviest. They land on relay nodes. They cluster on the walls of signal processing facilities. And they land on people's heads.

Specifically, they land on or near the neural port. Anyone walking through a moth swarm during peak migration will find moths alighting on their head, their neck, the area around the BCI interface. The moths settle there and remain, wings folded, antennae extended toward the port. It feels, according to consistent testimony from dozens of residents, like being chosen. Like something ancient and nonverbal has recognized you. Like the moth knows you are there, specifically you, and has decided to rest on you, specifically on the place where your biology meets your technology. It is electromagnetic attraction. The moth is sensing the signal emissions from your neural hardware and orienting toward the strongest source. It is not mystical. It is not meaningful. It is physics.

But it doesn't feel like physics. Every autumn, during the migration, the Shelf becomes briefly reverent. People walk slowly through moth-thick air with insects resting on their shoulders, their hair, their outstretched hands. Children collect them gently. Night market vendors sell moth-themed food and art. For three weeks, the Shelf — pragmatic, hard-edged, unsentimental — treats a swarm of insects with a tenderness that borders on worship. Then the moths leave, as suddenly as they came, and the Shelf goes back to being the Shelf. Nobody talks about the moths until next year. And next year, when they come again, the tenderness returns, as reliable as the migration itself. It is probably just electromagnetic attraction. Probably.