By Doris Lin
Fruit flies will follow the scent of the fruit down into the opening at the bottom of the cone, but once inside, they cannot find their way back out. After a couple of hours, you will probably find some fruit flies in your trap. This is where the humane part comes in: Take your trap outside, remove the tape and remove the paper cone to release the fruit flies.
Don't let your trap go unchecked for longer than overnight. You don't want to keep them trapped for too long, and if they stay in there for more than a day, the eggs will start to hatch.
Chances are, you didn't catch all of the flies in the first couple of hours, so you'll have to re-set the trap. To re-set the trap, remove the bait, replace it with a new piece of fruit, then tape the paper cone back into place. If you continue to use the same piece of bait, the eggs on it will hatch and you will end up breeding fruit flies inside your trap.