Mosquitoes have a pretty good sense of smell.
A mosquito can smell you and the gases you produce from as far as 30 feet away.
So the mosquitoes can sense you when you're 30 feet away so even if you have no mosquitoes near you at the moment as soon as the mosquitoes smell you they will likely be heading your way to bite you.
You can keep mosquitoes away from your patio or wherever you're sitting or playing by setting out a fan to help blow the mosquitoes away.
Mosquitoes will go away from the area when you have a fan blowing air around you.
You can also plant some garlic plants to help keep the mosquitoes away or get a mosquito magnet that uses propane to attract the mosquitoes and then it sucks them in and kills them.
I have a mosquito magnet and although it's pricey it's well worth the money as it really kills the mosquitoes.