In just 9 to 14 days, after hatching, the monarch catepillar is about 2" long and is now full grown. The caterpillar has eight pair of legs. The first three pair of legs will later become the butterfly's legs.A monarch caterpillar sheds its skin five times during the larval stage. Similar to the way a snake sheds its skin when its body has outgrown the skin, a caterpillar does the same. A new, larger skin is always waiting under the one that is shed. See the caterpillar's shed skin laying just behind its tail end?When the caterpillar is full grown it usually leaves the milkweed plant. It crawls (sometimes 30 or 40 feet away from the milkweed) until it finds a safe place to pupate. The caterpillar makes a silk-like mat and then attaches its last pair of legs to the mat. The caterpillar allows itself to drop and then hangs there, upside down in a J-shape, for about one full day.
