SRD:Giant Fire Beetle

=GIANT FIRE BEETLE=

These luminous nocturnal insects are prized by miners and adventurers. They have two glands, one above each eye, that produce a red glow. The glands’ luminosity persists for 1d6 days after removal from the beetle, illuminating a roughly circular area with a 10-foot radius. Giant fire beetles are about 2 feet long.

See Wikipedia Entry: Beetle