A Curious City listener collects Christkindlmarket mugs. But there’s one mug in her collection without a year on it. We go in search of that lost year.

A curious listener asked why he saw an aviary at O'Hare Airport. It turns out, it isn't an aviary at all — it’s a trap for an invasive species of bird.

Airplanes aren’t the only ones flying around at the airport. Birds often get stuck inside the terminal, and they can be a challenge to get out.

November is National Native American Heritage Month, a time to celebrate and recognize the history, culture and contributions of Indigenous people in our country. If you look around Chicago, you see echoes of Native American history in names like Washtenaw, Skokie and Wabash. But Indigenous history is often presented from a settler or non-Native perspective.

Today, we get into a project out of the Newberry Library called “Indigenous Chicago.” Through art, education and collaboration, its goal is to change the dominant narratives about Chicago’s history with the overarching message: Chicago is, and always has been, a Native place. It all began a few years ago with conversations within the Native community.

“One of the things we heard over and over again was this issue of invisibility,” said Rose Miron, director of the D’Arcy McNickle Center for American Indian and Indigenous Studies. “Native community members found that there were far too many people who didn’t understand the long history of Chicago as an Indigenous place, but also didn’t realize that there was a large contemporary community here today.”

“Indigenous Chicago” is a collaboration between representatives of tribal nations and includes multimedia art, oral histories, public programs, educational curriculum and an exhibition. Curious City’s Erin Allen spoke with curators Miron and Analú María López, the Ayer Librarian and assistant curator of American Indian and Indigenous Studies.

Chicago histories usually start in 1830, but Native Americans were already settled in the region long before that. Curious City fills you in on what some history books are missing.

When you think of a family business, one of two images probably comes to mind: either the mom and pop shop around the corner or the dysfunctional family from “Succession.” But actually, “it could be anything,” says Jennifer M. Pendergast, family enterprise consultant and professor at Northwestern University’s Kellogg School of Management.

Last episode, we looked into the oldest family business in Chicago. And this got us thinking about family enterprise in general: Why do family members end up in business together? What happens when they do? Should they?

Curious City’s Erin Allen sat down with Pendergast to talk about this, plus why she says family business is the “backbone of the economy.”

Tracking down the oldest family business in the city is not as easy as it seems. The city’s business records only go back to 2002. Time for a fishing expedition.

A Curious City listener wanted to know about the decline of frogs in our area. We looked into what’s been happening with these species over the last couple decades in Chicago.

It turns out, frogs are some of the animals we call “indicator species.” How well or poorly they’re doing in their habitat can tell us about the health of our own. And they’re not the only ones; there are numerous plants and animals that serve as nature’s alarm system, so to speak.

Erin Allen talks with conservation researcher, Dr. Allison Sacerdote-Velat, about the indicator species that are most vital to us in the Chicago area and why we should be paying attention.

Frogs have been on the decline in the Chicago area. The health of the frog population tells us a lot about the health of our environment.

It’s spooky season, a time when we often visit haunted houses and think about the paranormal. And if you live in the Chicago area, you’ve probably seen billboards and ads for the Old Joliet Haunted Prison. But at one point, it was an actual prison. Whether you believe in ghosts or not, questions about the paranormal can serve as an entry into the historical context of a place. Last episode, we visited the Old Joliet Prison to look into a lister’s question about whether it’s haunted. And that got us thinking about the ethics of “prison tourism.” Is it OK to take a place where people suffered and died and turn it into a site of entertainment? Today, we get into this question and more with Hope Corrigan, who reported on it for The Marshall Project.