Why do flies bite before is going to rain?

it has always been my ( and many others) experience that they do. not one idiot on the internet can answer why, citing everything from invalid wive's/farmers tales to them seeking shelter to not believing they do. seeking shelter does not explain attacking you! (most of these people probably spend a lot of time in the city or high rises) today i was swarmed so badly before it rained i ran from the garage to the house, i could not keep them off me. i am also diabetic which the explanation is the high blood sugar that they bother me more than normal ( i can be the only person in a room full of people they go after), but even normal people get attacked like pirhanna when it's going to rain.

so as i said, YES, although no-one can explain it or even believe it.

a bad answer is worse than no answer, which is all i can find. and flies do 'bite', they actually regurgitate stomach acid on you causing a burn, i have been biten many times, and sometimes it's through your socks, you don't notice them until a terrible stinging alerts you, when you swat and look, it's a common house fly!

another thing people can not believe-that a fly can bite.