Scientists at zoos work to protect all kinds of animals, from ones found on the other side of the world to ones right in our backyards. At the Lincoln Park Zoo in Chicago, scientists study wild Eastern massasauga rattlesnakes to help conserve the species. These snakes live in wetlands and grasslands around the central United States, and every spring, Lincoln Park Zoo scientists head a few hours out of the city to count the rattlesnakes. The scientists place harmless tracking devices in the snakes, similar to microchips for dogs and cats, and measure the snakes to get a better sense of what makes for a healthy snake habitat. In a recent trip, they found fifty snakes in just a single day!