Purple martins are good, but bats are better, since they hunt and feed at dusk when martins are roosting. I have had no sucess with luring bats to my houses, though.
Golly.... we have a TON of bats. I never knew it till we went out in the pasture at night... They were everywhere.
We don't have any mosquitos really.
We have a light like a street light in our front yard, we live in the country, it attracts moths that attract bats. You can see them darting in to catch the moths.
Becky