Perfect spots for em. Grassy banks around rivers/lakes. I'm always walking rivers. Last 2 weeks seeing decent populations along St. Croix, Mississippi, MN rivers.
Interestingly, same locations/time last year had remarkably more fireflies. Concerning. (Based solely on my obsvs)
Lilydale Regional Park and Theodore Wirth Park are great places to catch lightning bugs/fireflies in the Twin Cities.