The Slimy Underworld That Emerges After the Rain

After a Good Soak, the City Comes Alive with Rare Snails, Poisonous Mushrooms, and Slug-Like Molds.

You know that earthy smell that comes just as it begins to rain after a dry spell? It has a name. Scientists call it petrichor.

When I smell petrichor, I get excited: Rain is a personal and professional obsession. I begin keeping close tabs on the window while I check weather reports for the forecast. As the manager of citizen science (getting the community involved in scientific studies) at the Natural History Museum of Los Angeles County, I start making a list in my mind to share with others. What mushrooms …