Mosquitoes

there must be a godzilion of them out there, i've been rendered sleepless because of them.
don't know how they get in, there's mosquito netting in my room and i do give the room a good spray before retiring for the nite.
2 days back, my wife and i were having killing mosquitoes in my room by the dozens, it's a nightmare ! went to sleep well after our sleeping time.
anyone knows any good tip for keeping mosquitoes out ?
going home early to spray them mosy !