Caterpillar Condo and Metamorphosis Hut




Introduction: Caterpillar Condo and Metamorphosis Hut

About: I'm an animation director by day and Queen of the monsters by night. I picked up most of my costume and prop building skills through hands on experimentation with materials. Experimentation led to addictio...

A few of my friends and I planted milkweed earlier in the year as part of the effort to restore habitat and breeding spots to the Monarch butterfly. My plants didn't take off as much as I'd hoped, but my friend's plants flourished and attracted lots of butterflies, who then laid eggs. I was gifted with 5 two day old caterpillars to raise.

In this 2-in-1 Ible I'll take you through the whole Monarch rearing journey. I'll show you how to build a protective pod for your caterpillars and their host plant as well as a companion hanging hut they can be transferred to when they're ready to metamorphosize. We'll also review some care tips for the creatures themselves to help make sure you complete the journey successfully.

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Step 1: Why?

You may be asking why the caterpillars need a "condo" in the first place. Our structure accomplishes several very important things:

1) The netting protects the caterpillars from predators by walling them out. While monarch larvae are toxic to birds, we have some pretty stupid doves in our neighborhood and I wouldn't put it past them to try. Also, some varieties of wasps and spiders will also prey on young caterpillars if given the opportunity. Give you host plant a once over to ensure it is clear of other insects before netting your caterpillars in.

2) The netting and tomato cage limit plant movement and minimize the chances that wind and weather will knock your caterpillars off. If they do fall, the netting keeps them close to the plant and re-directs them right back to the food source.

3) The netting around our host plant is a visual signal for other people (neighbors, the gardener, the mailman, etc) that something special is going on with this plant. It lets them know they probably shouldn't mess with or move the plant without consulting you first. This protects your caterpillars and the health of their host plant. If you live in an urban area or apartment like I do, this is a significant issue. Maintenance workers often move tenant belongings to do repairs without thinking much of it, but this red netting says "STOP --ask before you touch."

Step 2: You Will Need...

Caterpillar Condo:

Tomato Cage -- Mine is a plastic and PVC one from the dollar store, but metal will also work.

Medium-large Pot

Measuring Tape

Fine Mesh Netting --I'm up-cycling an old bed canopy that the cats partially ruined with their claws. Maybe you have extra tulle left over from wedding decor or another type of netting just waiting in your fabric stash. Festive colors look great in the garden!

Scrap Cardboard --Mine was pulled from our apt. recycling bin. Choose something thicker like a shipping box over thin cardboard food packaging.


Plant Clips --Again, dollar store. You could also use binder clips or clothes pins.


Host Plant --In my case, this is a narrow leaf variety of milkweed. Different species require different host plants, so if you're mail ordering caterpillars to raise, research their needs beforehand.

Metamorphosis Hut:

Scrap Cardboard (same)


Hot Glue Gun

Fine Mesh Netting (same)

Plastic Aquarium Tubing or plastic coated wire --we had some in our craft bin

Twist Ties


Step 3: Before You Build

If you have eggs or very tiny caterpillars, it may be best to keep them in a small nursery container for a few days before putting them on the host plant in the pod. This allows you to monitor their health up close and with ease. If they were on the host plant you'd be upside down with a magnifying glass trying to find them and might accidentally hurt someone if you grab the wrong leaf at the wrong time. The nursery phase is also good because it gives you time to get your supplies together.

An ideal nursery container is transparent plastic or glass, and preferably shallow (no need to jam your hand in trying to find anyone). The sealable lid should either have air holes poked in it or have a section of mesh to allow air flow. My nursery is a tub I usually buy super worms in for gecko food.

Provide fresh host plant leaves daily.I like to run them under the sink before giving them to the caterpillars to rinse away pollution grime and any harmful residues that may have drifted over from other peoples' gardens. There is no need to provide water! Creating pools of water in the nursery only creates a potential drowning situation. The water from your rinse and the moisture inside the plant leaves will be enough to nourish the caterpillars.

As food dries up and caterpillar poop accumulates, you will want to clean the nursery. Use the tip of a paint brush to gently guide tiny caterpillars onto a fresh leaf before discarding the old. Remember to check both sides of a leaf before pitching it, as they often like to hang out on the underside. Carefully set aside your fresh leaves and caterpillars for a moment and tap the poop pellets into the garbage before replacing everything.

Your caterpillars will grow quickly and should be ready to go to the host plant at age 4-5 days.

Step 4: Plant Base

If you don't already have a thriving host plant, you'll need to purchase one. Since my original plants didn't reach the size I'd hoped, I bought a more mature plant that I was sure could sustain 5 caterpillars. Be smart about how many you can support -- they will eat a LOT as they grow and you don't want to run out of food. As much as I would have liked a dozen babies, I knew that would not be a responsible.

Find the pot you wish to transfer your host plant to. The store's pot was a nice size, but I wanted to give the milkweed just a little more elbow room to grow.

Turn the pot upside down and trace the widest part of the mouth onto your cardboard.

Cut out the cardboard circle you just made.

This will be the base of you pod. Its purpose is simply to add some structure and control to the bottom section of your netting.

Transfer the host plant to the desired pot. If the branches extend beyond the bounds of the pot, you may use some plastic plant clips to binds them together. A tighter cluster will be easier to fit inside our netting and you run less risk of knocking leaves (and caterpillars) around when you open and close the net.

After your branches are bound into more of a column, install the tomato cage.

Step 5: Netting Measurements and Assembly

Use a measuring tape to get the approximate height of the total unit; top of the plant to the bottom of the pot.

Add at least 1ft to that measurement. This will be your height.

Now measure the circumference of the tomato cage. If wrapping a measuring tape around the actual hoop proves to be tricky, you can use the formula" Circumference = pi x diameter" to get something close. Using that formula, I came up with just over 28 inches. I added 2 inches to account to seam allowance and a little wiggle room for the plant, for a final measurement of 30 inches.

Measure and cut a rectangle out of your netting material. Cutting net can be tricky. Later as I worked on the Hut I found that it's actually easier to manage if you lay your net yardage out on carpet. The carpet fibers grab the net and help hold it still for you. Out here on the cement, my cutting was pretty raggedy and I needed someone to help hold the net taught to keep the lines straight.

To assemble the pod sleeve, we'll sew two easy lines on the machine.

Fold the rectangle in half short ways. If your mesh is nice and soft like mine, it will be pretty unruly. Pins won't be much help since they'll slip right out of the net. Instead, you can apply some clear packing tape to the short edge to help wrangle everything.

You can use the tape as a guide or sew right through it. I used contrasting white thread so you could see it, but you can match your netting if you like. This part will be under the base, so you won't see it. I sewed through the tape, with my machine on a thread tension setting of "2". Just getting the short edge locked down made the long edge much easier to handle.

Now sew the longer edge. I just went slowly and held the two halves together as a went, and had no trouble.

Leave the top of the sleeve OPEN.

Turn the sleeve right side out. You should have a nice long rectangle.

Step 6: Easy Installation

Slip the cardboard base into the bottom of your net sleeve so that the seam (the one I taped) is on the underside.

Set your potted host plant on top of the cardboard base and begin working the net sleeve gently up around the plant. It will be fitted to your tomato cage cage, but should not be tight or difficult to work with.

Use plastic plant clips (or binder clips or clothes pins) to secure the netting to the top hoop of the tomato cage. This will allow you to open and close the top without having the whole thing slide down.

Close your top by loosely knotting the excess netting.Do this immediately so that no unwanted pests get on your plant when you aren't looking. Simply undo the knot to access the plant for food harvesting or caterpillar transfer. Your condo is ready for residents!

Step 7: Moving In

When your caterpillars are about a week old and an inch long you can be sure they're ready to move out of the nursery and into the condo. I decided to move the two largest ones in ahead of the others since they were probably the ones eating all the leaves in the nursery.

Two methods of safe transfer:

1) Encourage a caterpillar onto the tip of a paintbrush. You may find that they have little silk strands making them stick to the container. Do NOT pull away quickly or the caterpillar will probably get yanked back. Lift away gently and, if possible, clamp of the silk threads with your fingers to severe the bond.

Place the paintbrush tip on or near a host plant leaf. The caterpillar will quickly disembark.

2) If your caterpillar is clinging to the remnants of an old food leaf, simply pick up that piece and transfer it into the condo. You can set it among the leaves or put him on the dirt and let him choose where to climb.

Check in every day to monitor their feeding and health. Generally you will not need to open the netting and do anything for them. If you notice that they are leaving a lot of poop on the host plant, you can tap that way or sweep it off with the paintbrush to keep the food source clean. They will spend another week or so in the condo totally destroying the host plant and doubling in size.

Note: When your caterpillars have completed their metamorphosis and moved out of the condo, you can unsheathe the netting to allow butterflies to enjoy the host plant, and potentially lay more eggs. Just be aware that once you open up your plant to the world, unwanted, predatory insects may join in too. Before hosting another round of caterpillars, remember to give your plant a good visual examination to remove anything that might harm caterpillars.

Step 8: Metamorphosis Hut

The close quarters of the condo won't be an ideal place to monitor your chrysalis activity or for the butterfly to hang and dry their wings, so it is best to have a clear space to transfer them to. A number of nice butterfly kits are commercially available for this phase, but if you're in the mood to keep up-cycling or find yourself in need of a hut faster than one can be shipped to you, this is easy to make and uses most of the same techniques we just did for the condo. Pretty much anything beats a mayo jar with holes in the lid, which is how a lot of us probably raised butterflies as a kid!

Cut a ring of hollow plastic aquarium tubing. You could also use plastic coated wire, if you wish, but keep it small and light. This ring will be the diameter of your hut space. Since we've already figured out the netting measurements for a 9 inch diameter circle, I'll just mirror that here.

Hot glue the ends of the tubing together. Hold until the bod is firm.

Trace your ring onto scrap cardboard and cut out the shape. This will be the hut floor. The floor may become soiled as your butterflies drip dry, so know that this can always be traced and replaced when you need a new one!

Cut a rectangle of your netting material that reflects your desired hut size. In my case, we know the width estimate already (30 inches). Height can be whatever you wish. I went with 24 inches to keep the hut a very manageable size.

Sew the bottom edge first and the side edge second, just as before. You'll end up with something that resembles a produce sack.

Put the cardboard base into the bottom of the sack. You'll notice it looks a bit sloppy, since you're essentially putting a round peg into a square hole. To fix this, turn the piece over and tie the two sack corners into a small central knot. This will tidy the whole thing up.

Now place your tube ring inside the sack, on top of the cardboard.

Gather the excess netting at the top as if you were going to carry it like a bag. Knot it off close to the ends of the netting.

Holding the edge of the cardboard between your thumb and finger, turn the hut upside down. The tubing will fall right into the place it should be secured, giving you the height for the space.

Set the hut down on a work surface, collapsing the netting, and secure the tubing in place with twist ties. Four equi-distant ties worked well to support mine.

Now you can hang the hut by the top tassel and the structure will remain.You can hang it from a hook by the netting itself or attach twine.Don't worry if the cardboard floor tilts slightly. That may actually be a good thing --allowing caterpillar waste to roll away and get caught by the excess netting below, where it won't interfere with their health before you can dump it out.

Step 9: Hanging the Hut

If you'd like to transfer your caterpillars over to the hut in the last day or two before they build a chrysalis, that's a fine choice. Doing so avoids the much trickier process of transferring them in chrysalis form. Use either the paintbrush or the leaf caterpillar transfer method discussed earlier to avoid any squishy casualties.

Lay the hut on a flat surface, with the top of the netting open. Transfer your residents.* Remember to provide them with host leaves to munch on until they are actually ready to pupate.

Notice in the 5th and 6th photos I have a lidless nursery container in the bottom of the hut. This ended up being a nice solution for keeping food waste and poo contained. The caterpillar can climb out when he is done and make his way to the top, and all the garbage is waiting in one spot so I can throw it out later.

Re-knot your netting at the top and hang. To suspend my hut, you could use a free standing wire plant hanger, like the white one shown here. You could also suspend it from a garden hook, garden flag staff, or hang it from a tree limb using twine. If your night time temperatures are chilly, like mine have been lately, you might consider an indoor hanging solution for the evenings. Your netting will easily hang from simple hardware hooks you probably already have in your home. I used a hook under my toy shelf that normally supports a small marionette puppet.

If you have cats or dogs, make sure the hang spot is high up or secluded so nobody is tempted to bat at caterpillars!

Remember to close the top fully and securely.We want to continue to protect the caterpillars from predatory insects and also contain them now that they're more likely to wander around.

If needed, you can access the inside by gently untying your knot and lowering the net. Even if you have chrysalises hanging from the roof of the hut, you can still get in --gentle, careful movement of the net should not harm them. Obviously, do this as infrequently as possible. If you see a caterpillar hanging in a "J" shape that means he is about to change and should not be disturbed until the chrysalis hardens.

Step 10: Safe Chrysalis Transfer

NOTE: Only transfer a chrysalis if it is necessary. If it is in a precarious place or somewhere that does not provide enough space for the butterfly when it hatches, those are good reasons to move one. Don't just do it because you can. Excess handling = opportunity for damage.

Two of the caterpillars in my store bought hut decided to hang in a really tricky place near the opening. Fearing that this might not be the safest place, I decided to transfer them a little lower on the netting. The following steps were gleaned from, so this is approved and safe :)

Carefully tie a thread around the "cremaster" (the little black stem thingy) at the top of the chrysalis. You may wish to use a thread that contrasts your hut so it's easier to see your work.

*It's ok if your chrysalis lays horizontal for a moment while you do this. Just make sure when you re-hang it that everything is vertical. The chrysalis must hang vertically for everything inside to form properly.

Using a toothpick or other small tool, gently lift the edges of the silk attachment away from the net/ leaf/twig/whatever.LEAVE THE SILK ON THE END OF THE CREMASTER. It will help keep your thread from sliding off the end.

Route both ends of your thread through a new place on your netting. Double knot to secure.

If you have more than one chrysalis, be sure you leave enough room between them. The hatching butterflies will need a bit of elbow room. I've noticed that caterpillars do seem to like hanging near each other, often 1.5-2 inches apart. I re-installed these two buddies approx. the same width away from each other as they initially hung themselves.

Step 11: Hatching and Release

When a chrysalis turns dark it is actually becoming transparent. The darkness you're seeing is the folded up monarch inside. Seeing this means you can expect a butterfly in the next 24 hrs or so. The first photo shows the contrast between normal and almost ready. I did do a little photoshop color adjusting here to remove the red tint of the net from the chrysalises, so you can see the difference very clearly.

If there's a chance you won't be home when the butterfly hatches, remember to leave a little "nectar" to give them energy in their first hours. This can be something like a cut open slice of citrus fruit, or you can prepare a nectar mixture like this one, providing either a shallow dish or a saturated sponge the butterfly can stand on. They taste with their feet, so make sure the food is accessible to perching. *Simply mixing sugar and water is not advised, since the sugar can re-crystallize inside the butterfly's stomach if it gets too cold.

When a butterfly emerges the wings will be crumpled and wet. Allow around 3 hrs hours for them to hang undisturbed, letting the wings dry out. You may notice some clear to brown/red fluid that looks a little blood-like, collecting in a puddle beneath the butterfly. This is normal and will usually wash out of your netting in the end.

The 4th photo shows the two string attached chrysalises, just to prove they do hold up fin to support a hatching.

When the butterfly is able to beat the straightened wings and flutter, it's time to go outside!

Handling should be kept to a minimum to decrease the chances of accidental injury. That said, it IS ok to hold the wings gently as a means of transferring the butterfly into a carry container or putting them on a plant. The whole thing about your fingers rubbing their flight-giving scales off is a myth.According to monarch, monarchs are actually a bit sturdier than other butterflies and moths, seeing as they have a big migration ahead of them. One or two careful handlings for transportation is not going to ruin them.

I used a former nursery container to take my first butterfly outside since the metamorphosis hut still had a bunch of chrysalises in it. The second round was 3 who all hatched at once, so I just carried the entire hut outside to a kind neighbor's garden (with permission). I watched the monarchs take their first tastes of real flowers before taking off into the SoCal air. The last gal hatched a day later and was also released in the garden.

I hope this Ible has inspired to you take part in the movement to restore the Monarch population, or foster whatever species of butterfly/ moth you find interesting and available. Whether you plant milkweed locally, construct a caterpillar condo to protect larvae, raise butterflies to adults and send them on their way, or simply put out butterfly feeders for passers by, you're doing an important part for nature. If you enjoyed this guide please remember to cast a vote in the Outdoor contest.

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    13 Discussions


    Question 11 months ago on Introduction

    can you please tell me where you found that specific netting? I am looking for a large amount of it for shipping plants. Thank you,


    Reply 11 months ago

    This was a scarp of bed canopy. I'd look at a fabric store because they should have something similar on rolls.


    4 years ago

    super! our county is getting ready to get involved with monarch preservation and the ibles are going to be a big help


    Reply 4 years ago

    Wonderful! My key piece of advice is make sure you have plenty of milkweed ready to support the caterpillars. My last batch in December completely stripped my plants and garden centers weren't carrying milkweed anymore. The caterpillars spent their last instar eating the stems and whatever else they could find, and the resulting butterflies were much smaller than normal.


    4 years ago

    super! our county is getting ready to get involved with monarch preservation and the ibles are going to be a big help


    4 years ago on Introduction

    Brilliant! This is a great way to solve a problem (and frustration) I've always had with monarch caterpillars - thanks for this!


    Reply 4 years ago on Introduction

    Glad it'll help you. I found it to be great in terms of keeping everyone safe and getting as many monarchs to maturity as possible. I just set my final batch of adults free last week and hope they'll make it back some day to lay eggs.

    Jumping spiders? The zebra striped ones? We do have those in our house too. Soooo I would assume they're not as safe as it seems. Great project though!

    Yes we get lots of monarchs here but form some reason we get lots of tiger swallowtails as well. They just love our dill and European parsley. Their caterpillars eat the leaves. Later they use it to potentially stink off and possibly poison the predators, warding them off.



    Reply 4 years ago on Introduction

    I wish we had more swallowtails in CA. As a child I raised a group of black swallowtails who came for the parsley in our garden. Such a beautiful family of butterflies!

    I know the little zebra striped guys you mean. I'd have to ask my friend to see whether those are the culprits. In any case, I wouldn't be too nervous about their presence. Totally harmless to people, but they probably seem monster-sized to a newly hatched caterpillar. My netting is small enough to keep them out, just in case they are the bad guys.


    4 years ago on Introduction

    VERY COOL!!.... I have had milkweed plants in my back yard now for a few years to help propagate the monarch butterfly... I seem to have a great crop of caterpillars all summer..


    Reply 4 years ago on Introduction

    That's great to hear! A few little condos might be a nice way to ensure everyone makes it to adulthood. The friend I got my caterpillars from was noticing that jumping spiders were eating the small babies and birds were attacking them as they became larger, and ended up bringing 40+ caterpillars into indoor enclosures to keep them safe. I've been happy to read about the many people who have made milkweed way stations on their property to help restore monarch habitat. The farm my mom grew up on used to be a major stop --trees heavy with monarchs in the fall--and now you only see a few pass through.


    Reply 4 years ago on Introduction

    Oh Yes!... Your condos are absolutely the best and safest way to help out.. I do notice that I loose some but I didn't know what happened to them... I never knew about the spider attacks.. Interesting... Thanks for sharing!...