Do Insects Have Bones?
Insects do not have bones. The outer part of an insect’s body is made up of a tough material, which is called chitin. This material is the insect’s skeleton, on the outside, so it is called an exoskeleton. The shell skeleton encloses the insect’s body like a suit of armor. Without this skeleton, the insect would be soft and helpless.
Beetles have thick skeletons, but flies and mosquitoes have thin skeletons. Many other animals, including snails, clams and crabs do not have bones either. Most of these animals also have shell skeletons that protect their bodies. Worms and some slugs have neither bones nor shells.
Wings, legs, joints — all these parts of an insect are made of insect cuticle, a substance that’s actually much tougher than bone. It’s not made of cells, like your skin is, but instead is more like your fingernail, made mostly of proteins secreted by underlying cells.
The secreted proteins are supported by chitin, a natural polymer that provides the cuticle’s strength and prevents tearing. Different parts of the insect have different proteins, so the cuticle’s strength changes according to body part.