One Saturday morning as I was cleaning the caterpillar cages, I noticed one of the eggs looked dark on top. Then I saw the egg was moving and realized I was watching a caterpillar hatch!

tiny caterpillar climbing out of its egg

I thought I would remember all of the details of this caterpillar’s life – when he hatched, when he molted, and on and on – but of course I didn’t. It’s hard enough to remember with just one caterpillar, but we were taking care of six and, eventually, nine. But I did take a photo every day, with a dime as a reference for his size.

July 18 – newly emerged and eating the egg:

eating the egg

July 19:

on a paper towel, roughly the size of the flame on a dime

July 20:

on a leaf, much bigger than the flame

July 21:

half the size of the dime's torch, first visible tentacles

July 22:

as tall as the torch, with a recognizable caterpillar face

That night, I found him hanging by a silk thread off the side of the cage. I hadn’t seen anything like this before – I didn’t even realize they spun silk for moltings until this moment – and didn’t know what to do. Was he stuck? Was this part of the molting process? I wasn’t sure if I should intervene or let him figure it out.

But 20 minutes later, he was still there and appeared to be struggling because he was twisting and turning, and was even folding himself upside-down, seeming to be trying to bite at the spot where he was stuck. I decided I had to do something, so I gently brushed a Q-tip on the side of the cage, sweeping him onto the “floor.” He then quickly walked off the thread himself, and I realized I had done the right thing.

July 23:

about the same length but with longer tentacles

July 24:

almost as long as the dime

July 25 – suddenly, they get really big really fast:

longer than the dime

July 26:

tentacles have curved over

July 27:

twice the diameter of the dime

July 28 – last day before the transformation:

more than twice the dime's diameter, and fatter

Night of July 28 – getting into position. Their bodies are shorter and fatter at this point.

looking down onto the cage at the underside of the caterpillar

Morning of July 29 – hanging from the silk pad:

looking down onto the cage at the caterpillar in J position

Later that morning, a chrysalis:

chrysalis still with stripes, about 1.5 times the diameter of the dime

Eight days later, the green is gone and orange-and-black wings are showing through:

chrysalis from above

The next morning, I woke up early to try to catch the emergence. And then I waited… and waited. Two hours later, he finally emerged:

chrysalis from the front, with the first panel open but butterfly completely inside

chrysalis from the side, with one folded leg poking out

starting to slide out the bottom

body out, antennae unfolded

all four legs holding on

front legs moved to the top of the empty chrysalis

abdomen down, wings back but small and wrinkled

looking straight at the abdomen with the dime as reference, about half the length

drying, wings still somewhat wrinkled

holding on tight to the chrysalis, wings smooth

And now I had confirmation that I was right to call it a male. (Though that was just luck, since you can’t tell the difference at the caterpillar stage.)

at the bottom of the cage with wings spread

Unfortunately, he emerged on the first rainy day in more than a week. Best practices say you shouldn’t release butterflies in the rain because they’re too light to tolerate raindrops, so this was the one I previously mentioned looking wistfully out the window:

hanging upside-down from a cage while looking out the window

The next morning was sunny, and he was ready to be released:

hanging to the side of the mesh cage, much bigger than a dime

One last comparison with a dime:

side view as he's hanging off my fingertips

Then I moved him to a black-eyed susan, and off he flew:

letting him climb onto a flower

More about our monarchs

It was only a matter of time before my noticing the goings-on of monarchs in the garden turned into fostering caterpillars in our kitchen.

two caterpillars sharing a leaf

According to several monarch sites, only around 5 to 10 percent of monarch eggs result in butterflies. The rest are struck by predators (including ladybugs!) or disease. And the population of adult monarchs that overwinter in Mexico has dropped dramatically over the last several years.

caterpillar in J formation

We’re doing our part to help the population rebound by bringing them indoors. I want to help them all, but we only have so much space (and time), so I’m doing the best I can with the ones in our care. This generation, that meant nine caterpillars: three brought in as caterpillars, six that hatched inside. There also were three other eggs that didn’t hatch.

one new butterfly and two dark chrysalises

The last six weeks have been a blur of eggs, caterpillars, moltings, milkweed, chrysalises, and wings. Plus dozens of milkweed leaves.

milkweed leaf with lots of holes

And poop. Lots and lots of poop. (Or to be more scientific, “frass.”) When they’re little, the poop looks like pepper flakes.

medium-sized caterpillar and frass

I don’t prefer the term “larva.” I know it’s scientific, but it sounds like something undesirable and writhing and creepy. I’m going with “caterpillar.”

Same with “pupa” – it’s a beautiful green chrysalis.

five chrysalises hanging in one container

The system I’ve settled with:

incubator (for eggs that haven’t hatched) – this would be better with a clear lid

small plastic container with a black lid

nursery (for the littlest hatchlings)

large gladware container

small cage and big cage for caterpillars, sorted by size, using nylons over the openings so they don’t escape

small plastic cage with nylons over the lid

laundry hamper for when a butterfly hatches but I’m not around to let it go for a couple hours. We found out with the first butterfly that after its wings are dry, it will be ready to start flying – and then it panics when it can’t climb back up the plastic walls.

plastic container with a butterfly ready for release

These hampers give them more space to move and even fly a bit.

mesh laundry hamper with three butterflies

I’ve gotten pretty good at relocating chrysalises – something I never thought I would do. They form the chrysalises in the plastic containers, but most days, leaving them there isn’t a good idea because I am not home to release them right away. One site suggests knotting dental floss around the cremaster, and that works well. I then tie it on the strap of the laundry hamper.

tying dental floss around the top of a chrysalis

I watched two caterpillars transform into chrysalises – a process that’s both strange and exciting.

The sites say that butterflies emerge after 8 to 12 days of being in a chrysalis. Our first chrysalis started turning dark on day 5, and by day 6 I was fearing the worst. There are a number of things that can happen, from tachnid flies to black death to the OE parasite. But my worry was unfounded: the butterfly was simply finishing earlier than expected! I was so relieved to see wings starting to appear through the chrysalis.

chrysalis with visible butterfly wings

Sure enough, at 8:20am – when I was in another room getting my things together to go to work – it eclosed (scientific term for emerged).

newly emerged butterfly that is still wrinkly

The emergence happens so fast, it’s very easy to miss. Once it even happened when I was in the same room, and I still missed it! But I did see two of the nine butterflies come out.

Then comes the release. Many of the butterflies arrived on work days, so I needed to come home over lunch to let them out. The first was released on a windy roller-coaster of a day. (Yes, I did get teary-eyed when she flew away.)

butterfly resting on a finger

We released second caterpillar at our friends’ brand-new home; their daughters named him Eric. He took a short test flight and then rested in a tree.

butterfly resting in a tree

One exciting day, THREE monarchs emerged!

three brand-new monarchs hanging onto their chrysalises

We had to keep two overnight – one because of weather (don’t release them in the rain) and one because we weren’t home during the afternoon – and they did not like being kept inside.

monarch in a hamper looking out the window

Though we did provide them with a delicious dinner.

wildflowers and a slice of watermelon

I’ve learned a lot: for example, the caterpillar I filmed “out on a stroll” in the garden was probably looking for a quiet place to molt. (Good rule of thumb: they know what they’re doing and don’t need help from humans.)

two caterpillars molting on the side of a plastic container

They eat a lot. Fortunately we have enough milkweed. They don’t seem to like the butterfly weed, even though plenty of eggs have been laid on butterfly weed. Now that it’s late in the season, though, the milkweed isn’t looking so good. I’ve been trimming it to encourage new growth.

And now: the final generation of the season is underway, the ones that will migrate for the winter. So far I’ve found two cats and four eggs. It’s a lot of work, but I think it’s worth it.

monarch with purple coneflowers

Order of emergence of our first generation:

  1. Wednesday 7/29, girl, 8:20am
  2. Saturday 8/1, boy, before 8:00am
  3. Tuesday 8/4, boy, 8:20am
  4. Tuesday 8/4 (should have been #3), girl, 10:15am
  5. Tuesday 8/4, girl, 10:35am
  6. Thursday 8/6, boy, 8:55am
  7. Friday 8/7, boy, unknown time
  8. Monday 8/10, girl, before 8:00 am
  9. Saturday 8/15, girl, before 8:00 am

More about our monarchs