You are correct!
I live in Austin, home of the largest Urban bat colony in the nation (world?). We have the Colorado river running through the middle of town, numerous creeks and streams here in the Hill Country. We have 1+ Million Mexican Free-Tail Bats, each eats 2x their body weight in 'skeeters' each and every night. That's a lot of 'skeeters'!
Assuming you don't have a bat colony nearby, the CO2 Insect Killer is the next best choice.