Even though they live in warm regions, velvet worms prefer cooler temperatures, coming out at night to clamber over the moist undergrowth. As velvet worms live in such humid environments, their bodies are hydrophobic. The small lumps covering their bodies are covered in scales that repel water, saving them from the risk of excess water intake.
Long and tubular, the velvet worm’s segmented body is covered in dimples known as papillae, resulting in their common name. They come in a variety of colours, including orange, red, brown, blue, gold, and white. Occasionally species will have multiple colors in striped or blotched patterning.
They can have 13-43 pairs of legs, which have no joints. The legs move thanks to different pressures of fluids in the legs contracting or relaxing the limbs. Each leg ends in a small pair of retractable claws.
As seen in these photographs provided by Nicky Bay, the velvet worm's head features a pair of thick antennae, one pair of beady eyes, and a mouth containing sharp mandibles, which look almost identical to the claws on their feet. Velvet worms can reach 20 cm (8 in) in length, but most species only reach 5 cm (2 in).
Females are usually larger than males and typically only produce young once in their lives. They vary in how they mate and how young are born; some velvet worms lay eggs, and others produce live young, but the majority undergo a process known as ovoviviparity. In this process, embryos develop inside an egg, but the egg is kept inside the mother’s body until the young are ready to hatch.
It would be easy to assume that these small creatures are some kind of centipede or a caterpillar that was a bit too stubborn about not wanting to grow up, but velvet worms are in fact neither of these. Velvet worms are part of a group known as onyhophora (“bearing claws”), containing about 200 species of them. Their closest relatives are tardigrades; you’re more likely to know them as water bears, the ‘indestructible’ animals that can survive in the vacuum of space.
Velvet worms are divided into two living families, separated by genetics and geography. The first family, Peripatidae, are longer than the other family, with more legs and mostly producing young through live birth. They are found in tropical regions, such as Central and South America, some Carribean islands, West Africa, and Malaysia. The second family is called Peripatopsidae, which is considered the more ‘primitive’ family. They are found mostly on islands in Oceania, with small populations also found in South Africa and Chile.
