- [Narrator] 150 feet underground

in 30 million year old caves

an unforgettable sight glitters in the dark.

The Waitomo Glowworm Caves in New Zealand

are home to about 30,000

endemic Arachnocampa luminosa glowworms.

They spend their days spinning silk nests from the ceilings

and then lowering threads to fish for prey,

much like a spider.

The luminescent bead-like strings are spell binding.

The glowworms use light to attract prey

and burn off waste.

The glow is created by a combination of chemicals

given off by the glowworm and the oxygen in the air.

The caves are ideal for the worms

as they need a dark, damp location

where their light can be seen.

The Waitomo Caves they call home

are named after the Maori words wai,

which means water,

and tomo which means hole or shaft.

And although they live deep underground,

the journey to see them is never one to disappoint.