Join the naturalists of the Eastman Nature Center for an event centered around the singing of frogs. Participants learn to distinguish common frog calls and other nighttime sights and sounds of the natural world in and around the Maple Grove area. 20 percent discount to groups of four or more. Ages 6 and up. $5 per person with optional $1 donation. 8–9:30 p.m. Eastman Nature Center, 13351 Elm Creek Rd.; 763.694.7700; threeriversparks.org.