The monarchs' send off has become an annual celebration for El Valor, a non-profit early childhood education provider on the city's Southwest Side.
The children see the monarchs grow from eggs, to caterpillars, to the iconic orange and black winged butterflies.
"They see how things change and how they morph," said Sinead Abarca an Education Supervisor and parent at El Valor. "So it's really teaching them how to see the lifecycle of a butterfly and how life changes so easily. And even when we think it's dark and there's nothing else. You get a beautiful butterfly."
Every year, monarchs take off from our area in September for an impressive migration from Illinois to Mexico. Some will start even farther north in Canada.
Their mighty wings fly them some 2-thousand miles south to spend the winter in the mountaintops of a very specific region in Michoacan. Their tree of choice is the Oyamel fir.
Millions of them arrive just in time for Día de los Muertos in November - every year.
"If you think about it spiritually, the point of Día de los Muertos is to have our ancestors come back to us right. And that's what it symbolizes," said Abarca. "Why they come back at that time, I really don't know. But it's just the perfect timing. It's magical."
It's so magical, even scientists can't explain it.
"They know how to fly south because they can keep track of time and they can tell a sense of direction based on where the sun is in the sky. They also can detect like Earth's magnetic fields a little bit like they have an internal compass built into their bodies," said Allan Lawrance, the associate curator of entomology at the Peggy Notebeart Nature Museum in Lincoln Park. "Now, how do they know to go to these specific mountaintops in Michoacan, where the butterfly sanctuaries are? That's the greatest mystery."
Lawrance says that while rearing Monarchs in captivity won't necessarily help build their population, it does help raise awareness. Lawrence said the monarch is not at risk of extinction anytime soon but it's a candidate for listing under the Endangered Species Act.
"The main factors that are affecting them now are one habitat. So the amount of area that they have available with nectar and host plants, milkweeds, um, pesticide exposure, pesticides mainly that are used and, and agricultural fields and climate change," said Lawrance.
"Many families with origins in Mexico are excited that they can contribute to the success of conservation programs in Mexico by planting milkweed and flowers in Chicago," Michael Rizo with the U.S. Forest Service said. "Families say they are sending their regalitos, or little gifts back to Mexico each September, and the families in Mexico are ready to receive them by planting habitat and taking care of the forest where they overwinter."
There is no other butterfly in the State of Illinois that migrates to a specific place and then returns back at some point in the season.
"And then once we reach late August again, that last generation to emerge will go back down to Mexico to the exact same spot that their great great grandparents had been," said Lawrance.
A fine example of perseverance and resilience.
"You would think a delicate little butterfly. How could it fly more than 2000 miles and make it down to Mexico? I couldn't walk that journey, especially not even within two months," Lawrance said.
You can volunteer to collect data on butterfly populations through the Illinois Butterfly Monitoring Network.