Cut off the tops of cardboard egg cartons and save them for other uses. Then cut the bottom sections of the egg cartons in half lengthwise. Turn the sections over and have the children paint them green, brown or orange (or whatever color they desire) to make caterpillar bodies. Help them poke pipe cleaners into the tops of their caterpillar heads to make antennae. Then have the children draw eyes and mouths on their caterpillars with felt-tip markers.