When you’ve got a tough exterior, there’s only one way to grow: Shed your skin.

Arthropods, the most abundant group of animals on Earth, all possess a hard outer covering called an exoskeleton, which protects them from predators and supports their bodies. From a crab’s shell to a ladybug’s shiny back, exoskeletons come in a many shapes and sizes, but most are made of the same fibrous material: chitin.

When a young arthropod is ready to grow hormones trigger its skin to begin molting, a process known as ecdysis. The outer layer of the exoskeleton, the cuticle, and the layer beneath, the epidermis, begin to form a new, replacement cuticle. The animal then takes in a