“After Dark Series: Fireflies”: Hudson Mills Metropark.
A Hudson Mills park interpreter leads an expedition to look for fireflies and discuss their glow, life cycles, and communication. Half-mile to 1-mile walk along slightly hilly mixed gravel trails. 9–10 p.m., Hudson Mills Metropark Activity Center, 8801 North Territorial Rd., Dexter. $5 (kids, $3). Preregistration required at bit.ly/hudsonmillsjuly. $10 vehicle entrance fee. 426–8211.