Larry Harder, age 12, of St. James, Manitoba, Canada, for his question:

Why does dead wood glow in the dark?

Many substances living or non living have a talent for glowing with a spooky light in the dark. When certain sulfide minerals are placed under a bright lamp, they glow in the dark with colored phosphorescent light. Some substances can make invisible ultraviolet rays give visible light. This quality is called fluorescence.

Certain plants and animals give off their own light in the dark and this talent is called bioluminescence. Certain bacteria give off a blue glow. Certain bioluminescent fungi give off their own yellow light. These non green plants are likely to set up housekeeping in logs and rotting wood. During the day, their pale light is lost in dazzling sunlight. But after sunset, they make the old wood glow in the darkness.