Plants or animals that take care of mosquitoes?

[BeasleyQ]

We recently moved to a new house with a large backyard. (Well, recently meaning September)
We were quite disappointed by the mosquitoes that plagued us - especially as there have been a dozen confirmed cases of West Nile in our new town.
Does anyone know of any plants or animals that do a good job acting as pest control?
We live in Northern Montana (zone 4?), so we only get these little suckers for a few months in deep summer until the first frost.
Unfortunately, we live very close to a river, which I assume, is where they're coming from.
The town sprays every morning (still haven't figured out what they're spraying yet), but although I can smell it in the air, it doesn't seem to stop my girls from getting bites....
I'm hoping to find something for our personal use in the backyard, but if there is something we could convince the town to try instead of spraying pesticide up and down every street, I'd be interested in that as well.
Someone mentioned bats recently, but I'm unfamiliar with the animals and am a little hesitant to suggest that to the town council....
Thanks!

[canadiyank]

Hmmm, nothing I've ever heard of. I know some places sell non-toxic "dunks" for ponds etc. but that's not really going to help if they're coming from the river/marsh. I've heard bats are good, I've seen places that sell "bat boxes," so that might be an option. There's a lot of mosquitoes at my folks' place and so we try to not be out at dusk (they seem more prevalent then) and spray them down with deet-free repellant.

[J3K]

Bats are excellent mosquito eaters. As are certain breeds of spiders and frogs.

I know that baby oil applied to the child deters those pesky 'skeeters .

And I'd most certainly beef up my efforts in determining what exactly they are spraying over the area.