Why Do Caterpillars Need To Shed Their Skin When They Grow Bigger But We Humans Do Not ??

Dear Ria,

 Caterpillars shed their skin in order to grow, because they have an exoskeleton, which means that they are enclosed inside their skin. The skin does not grow with them as their body grows hence, they have to move out of their skin as it becomes too tight for them. This process takes place 3 to 5 times in caterpillars till they are fully grown ,by the process of moulting.  In humans, skin cells also grow with the body cells.