Well I have the same problem. There are 3 methods I know of.
1) Don't bring anything sweet into your house. You probably don't like
this one so just keep all fruits and other sugary things in plastic bags
or something. Also try not to throw food scraps into the garbage. Or if
you do then just change the garbage a lot.
2) Take a small jar and put a little jamat the bottom. Preferably you
can sprinkle a tiny bit of cooking yeast on top. Then make a paper
funnel with a hole about double the size of a fruit fly. Tape the funnel
in the jar so that they can crawl down the funnel into the jar. The idea
is that they can't crawl back out. This one has the same concept as a
lobster trap, if you know what that looks like. They will lay their eggs
in the jam and then get stuck in the jar. You can then just wash out the
jar every once in a while, killing the flies as you do so.
3) Take a saucer and fill half full with vinegar. Then put plastic wrap
or a plastic bag and put it tightly over the top of the saucer. Poke a
couple small holes in it double the size of a fruit fly with a pencil or
something. The little buggers crawl through the holes and drown in the
All of these methods work very well and should probably be used in a
combination. You should put either #2 or #3 in each of the following
places: beside sink, in food cupboards, in fridge, beside garbage. You
would not believe the number of flies I've caught in these 2 types of