Some organisms naturally create light so they glow in the dark. The ocean is home to many bioluminescent creatures, from algae to deep-water octopuses, but you'll also find glowing insects (like fireflies), mushrooms, and bacteria! Write in the colors of the word of bioluminescence with this neon gel pen 6-pack. .7 mm tips Neon Gel Ink Each pack contains 6 unique colors: Stauroteuthis Deep Water Octopus Messmate Pipefish Firefly Agaric Mushroom Algae