Where do fruitflies and maggots come from?

[LennoxLewis]

If you leave an opened banana or melon as long as a single day, there's already tens of fruitflies near it (here in Holland), when you normally NEVER seen them peeking around for a piece of decaying fruit. So how do they know where the fruit is and where do they come from??

Same with maggots...

 

[DavidSnider]

They have a very good sense of smell and come from outside. That's pretty much all there is to it.

 

[Monique]

If the fruit was ripe when you bought it, it probably already had fruitfly eggs waiting to hatch. The fruitflies could also be coming from outside, where they homed in on the smell of your ripe fruit.

 

[bakiron1]

fruitflies come from maggots, and maggots come from fruitflies, and chickens come from Safeway