Question

why arthropods use to get rid of their exoskeleton?

Answer 1

I’m pretty sure molting is common to most arthropod (crustaceans, arachnids, insects,etc.). They shed their skin because their skin is really their exoskeleton and it never gets bigger. If an insect outgrows its exoskeleton then it has to get rid of it and grow a new bigger one. Not all arthropods do this:hermits crabs use the shells of other animals for instance. But even then hermit crabs have to go find larger and larger shells as they continue to grow.