Life Cycle of the Monarch:

After coming out of hibernation to find a mate, monarch butterflies migrate North and East to lay their eggs on milkweed plants. It takes about four days for the eggs to hatch into caterpillars. The caterpillars then spend the next 2 weeks eating milkweed in order to grow. Eating milkweed also makes the Monarchs bitter and poisonous to predators. Once full grown, the metamorphosis process begins. During metamorphosis, the caterpillar will use its silk to attach itself to a plant and form a chrysalis. The chrysalis phase lasts 10 days, during which time the caterpillar transforms into a butterfly. After emerging, the Monarch butterfly will only live for another 2-6 weeks. The Monarchs that migrate live a bit longer, from September or October to around April.

More Information:

Life Cycle Chart

Migration Chart

Image Credits:

Left side of banner is from http://www.inhs.illinois.edu/inhsreports/sep-oct99/specspot.html

Right side of banner is from http://www.outdoorlens.com/monarch-butterfly-pictures/