I have a mosquito infestation problem.

I've checked around the house and there are no stagnant pools, puddles or water, but in the evening there's a cloud of mosquitoes.

I left the bathroom window open last night, and this morning there were at least 70-80 mosquitoes around it.

The garage has Tiger mosquitoes (nasty farkers who will bite any time of day), which are kept fairly in check with the resident spiders (all huge and fat daddy long legs).

The other mosquitoes just hang around and don't bite much, but make me paranoid... specially after what I saw this morning.

I've sprayed the bathroom and they're all on the floor now.
How do I get rid of them outside?

Thanks.