Fruit fly trap

Get rid of the annoying fruit flies (Drosophila). Well, it is a war you probably cannot win completely, but you can significantly reduce their numbers.
1) get a suitable glass or cup - so you can see inside.
2) measure the rim diameter and scale the print to fit your glass. If you print slightly big, you can easily fix it binding a tape around the glass rim.
3) drill cca 1-1.5 mm holes to the inner cones. Make lot of holes, so that the flies can smell the lemon. See the pictures - I have cca 6 holes per cone and it worked fine. Also drill a hole at the tip of the cones if it prints too tiny. Too big - they will find a way out. Too small - they will stay outside...
4) take a squeezed lemon, put it in the glass, close it with the trap and see the flies coming in.
5) make sure to empty the glass before the lemon gets mildew or is rotten. It is clever to open the trap outside your living quarters :-)
6) use lemon or other fruit that is loved by the flies. I have tried a lemon concetr