In 1862 during the Civil War at the Battle of Shiloh in Tennessee, soldier’s wounds would glow blue. Those with more blue were likely to survive and it was called Angels Glow.

In 2001, a couple of kids and their microbiologist mom went on a mission to find out why. The soil contained Photorhadbus luminescens, a bioluminescent bacteria. They further found this bacteria lives in nematodes in the soil. The nematode burrows inside insect larvae then throws up this bacteria which releases chemicals that kill the host larvae and all the other bacteria.