Deep in the limestone caves of New Zealand rest colonies of glow worms that emit a blue-green light strong enough to illuminate the caves they live in.

These wonderful yet strange creatures are called arachnocampa luminosa. They're native to a northern part of the country called North Island.

Auckland photographer Joseph Michael documented the awe-striking creatures, which live in caves said to be as ancient as 30 million years old, by spending countless hours in the caves' ice-cold water.