See the delicate threads? (istock/Philartphace)

Under normal circumstances, being in a confined space with a bunch of larvae wouldn’t be at all appealing. (I mean, seriously, who wants to do that?) But when the larvae glow in the dark and dangle threads from the ceiling of a dark New Zealand cave, they suddenly become something very delightful and strange. Tens of thousands of these pre-gnat insects called glowworms are known to decorate cave ceilings in New Zealand like stars in the night sky. If you’d like to visit the planetarium, you should head to the Waitomo Cave, where tour guides will lead you into the cave depths for a look at the glowworms.

But let’s discuss these glowworms because I think they’re interesting. First of all, they glow in the dark for two reasons: to attract the opposite sex and to attract prey. It’s simple: They glow because they love you or because they want to kill you. Glowworms catch prey by hanging out on the ceiling of a cave and dropping down a glow-in-the-dark silk line, sort of like a fishing line (in the words of Roy Alexander). When a glowworm catches prey, it pulls up the line and eats its dinner. And in fact, it’s the glowworm fishing lines that really make the cave planetariums look so striking. How strange to see these delicate, glowing threads dangling from a cold dark cave? That’s something I’d like to witness.

For more on caves…
5 Most Amazing Caves
How Cave Biology Works
How Cave Diving Works