Typically, the larvae of tortoise beetles create a fecal shield with which they cover themselves. This shield can be raised and lowered (it is attached to the rear end), like an umbrella in a sense. It probably aids in protection from predators, or that is the theory. This one has not yet created its fecal shield and so it is a chance to see what these spiky things look like when not covered. See the next image for a look at a larva with a fecal shield.