Fireflies disappearing across America. Cause: light pollution. Streetlights, signs, windows — fireflies can't see each other. Can't mate. Population drops.
At Amish Farms
No streetlights. No electric windows. Darkness — real. A June night on an Amish field looks like sky inverted: thousands of lights below, thousands above. Stars and fireflies. Children catch them in jars (and release in morning).
Metaphor
To see light — you need darkness. Amish live in darkness (literally — no electricity). And see light the rest of the world has lost.