Why can stick insects regrow legs?

Answer: Regeneration through molting

Extra legs stored inside body — Wrong. Stick insects don't have spare legs stored. They regenerate lost legs through biological regrowth during molting cycles, not by deploying backups.

Regeneration through molting ✓ — Correct! When stick insects lose a leg (escaping predators), a small limb bud grows at the break point. With each molt (shedding exoskeleton), the new leg grows bigger. After 2-3 molts, the leg is fully functional! Young nymphs regenerate better than adults. It's true regeneration!

Stem cells rapidly multiply — Wrong. While cell division is involved, regeneration specifically happens during molting periods. The new exoskeleton allows the regenerated leg to grow and harden properly.