How Exoskeletons Protect Animals and Why They Molt

Next Generation Science

This educational video explores the fascinating world of exoskeletons, contrasting them with the internal skeletons (endoskeletons) of vertebrates like humans and mammals. It explains that while vertebrates rely on backbones for structure, a vast majority of the animal kingdom—about 97%—are invertebrates, many of whom rely on rigid external shells for protection and support. The video details the composition of these shells, made from a tough yet flexible substance called chitin, and categorizes key groups that possess them, including insects, arachnids, and crustaceans. The content dives deep into the biological pros and cons of having an exoskeleton. While offering excellent protection against physical damage and dehydration, these rigid shells present a significant challenge: they do not grow with the animal. This introduces the critical and perilous process of molting, where an animal must shed its old shell to allow for growth. The video provides stunning visual examples of this process, particularly featuring a cicada emerging from its old skin. For educators, this video serves as an excellent resource for biology units covering animal adaptations, structural biology, and life cycles. It visually demonstrates complex concepts like molting and muscle attachment in a clear, accessible way. Teachers can use the high-quality footage of diverse species—from weaver ants bridging gaps to crabs on a beach—to spark discussions about evolutionary design, the trade-offs of different biological structures, and the sheer diversity of life on Earth.