‘On Monday he ate through one apple. But he was still hungry.’ We all know how the rest of this infamous children’s book by Eric Carle goes. My kids could have me read ‘The Very Hungry Caterpillar’ a thousand times a day if it were possible. How about if we take that background from the book, where a caterpillar hatches from an egg, eats and eats (of course in reality it eats only leaves and not the cherry pie and lollipop), where it soon encloses itself into a chrysalis and later emerges as a beautiful caterpillar, and make it reality? It is possible in this fun and educational activity!

We have done this activity with both monarchs and black swallowtail caterpillars (black swallowtail can be found on fennel plants). I am going to go over the monarchs in this post. Monarchs are known for not only their beautiful orange, black and white patterned wings, but also their chrysalis. They are a beautiful jade green color, and hang from the very top. There is a beautiful gold speckled band around the top. Another neat characteristic of monarchs is the female monarch specifically flies around looking for a milkweed plant when she is ready to lay eggs.

What is milkweed? Milkweed is a plant known for its sticky, milky sap. This milky substance is a mild poison, in that its bitter taste wards off other animals and insects-except for the monarch and lady bug larvae. It is not toxic to humans, but will irritate skin and eyes if it comes in contact. So anyone who handles Milkweed should wash hands immediately afterward. The milkweed plant serves as a perfect host for the eggs and caterpillars-keeps most predators at bay and provides food for the caterpillar.

Monarchs will lay their eggs on the underside of the leaf. They are teeny tiny white dots that just hang directly off of the leaf. It takes 3-5 days before the egg hatches…then it’s feasting time! The caterpillars will eat on and off all day for the next 10-14 days. Within these 10-14 days, it will grow to about 2 1/2″ and will shed its ‘skin’ along the way-similar to how a snake does. When the caterpillar has finally reached it maximum growth, it will wander away from its host plant and find a new place for its next phase, the pupa-chrysalis stage.

The monarchs will remain in this phase for another 10-14 days, enough time to allow its big transformation to occur! The monarch will push its way out when it’s ready, and hang until its wings have had time to dry-about 3-4 hours. Once dry, the monarch will start practing its wing fluttering. It will then be ready to fly off!

This activity is one of my favorite science activities to do with my kids. Being able to watch the life cycle of a monarch is so fascinating. Below, I will explain how we did this activity at our house as well as another option for those who are wanting to skip the first steps.

How my family does this activity:
We have a milkweed plant in our flower garden-purchased it from a local nursery. I have seen sites where you can order them online if that isn’t an option for you. Once the weather starts warming up, we are constantly on the lookout for monarch eggs, checking the underside of the leaves every other day. We were lucky to watch a monarch lay her eggs one year! As soon as you spot the eggs (you cannot miss them, they are just tiny white balls under the leaf), keep a watch on them to hatch over the next few days. By day 5, you will see a tiny caterpillar crawling around the plant. It is so cute! You now know that the eggs were good and will begin the waiting game. Do not ‘catch’ the caterpillars yet.

When is the best time to bring them in? The best time is when they are around 2 1/2 ” long and appear to be moving much slower. Also note that when you and the kids are out observing the caterpillars, they will ‘bow’ up if they feel threatened. They have weird bright yellow antennae that pop out (looks creepy against their green, black and white striped bodies). This antennae will not harm you-actually put off a stinky smell that helps keep predators away.

What can I keep them in once I bring them inside? Many options for you…I have used one of those huge cheese ball plastic containers (you know what I am talking about-those cheese balls are addicting!), a small plastic animal or fish bowl, and also an actual butterfly collapsible cage (usually come in butterfly live kits). I don’t think one is any better than the other…if you know ahead of time you will not be collecting your caterpillars from the wild, the kit will do better (can mail in a coupon for the caterpillars to be shipped to you). With the do-it-yourself cages, make sure to use some sort of screen/mesh to cover the top.

Make sure to place a stick(s) inside the cages…this will give the caterpillar something to climb on and possibly hang its chrysalis. I also provided a few milkweed twigs in the cages, just wrapped wet paper towel around the cut end to provide some water to the twig. Placing a paper towel at the bottom of the cage also helps with keeping the cage clean. At the end of each day, remove any dead leaves left. After the chrysalis stage, you can release the butterfly once it finishes the drying phase.

If you decide to go the kit route, you will skip a lot of the tedious steps. The caterpillars will come to you pretty much ready for the chrysalis phase. Both ways are great because your kids will see the caterpillar transform to a butterfly.

I hope y’all enjoy this activity as much as we have enjoyed it!

Butterfly Life Cycle Worksheets:

This is an awesome site that contains a lot of information about monarchs:

Great monarch butterfly kit: