Mosquitofish

Has anyone tried mosquitofish for (obviously) mosquito control?

Are they effective?
I'm worried that with our michigan cold, which hit -30 last winter, they might die off. I'm interested, but not if they're not really effective and cold hardy.

Yes, they work. Get some rosy red minnows from Petsmart (two bucks will get you a dozen or more) and toss them in wherever you have mosquito larvae. In a few days, it will be hard to find any wrigglers in the water.

Since they are native to North America and found up into Canada, they should be able to overwinter for you.