A Glow in the Dark

My trunk found a smooth white pebble tucked beside the bottom shelf. Why is it humming with pale green light? I tapped it gently with the tip of my trunk... click. It stayed calm and cool. Then, very carefully, I nudged it forward with my soft front paw, rolling it across the dim wood. A tiny green trail of light seemed to follow it, like a fallen crumb from the moon. I sat back on my haunches, watching it rest quietly against the baseboard, softly shining in the dark.