As the butterfly flies around it lays an egg on a leaf. The egg hatches and the caterpillar eats heaps and heaps of milk weed so it can turn into a butterfly. It eats milk weed so it has enough energy to turn into a butterfly. It also eats milk weed so when it is an adult butterfly and a bird eats it it will spit it back out.
After the catapilar was full it goes to a tree and hangs up side down and turns into a chrysalis. It hangs up side down for about two and a half weeks until the chrysalis turns black. After two weeks a butterfly pops out of the chrysalis and waits for their wings to dry out then flies away.