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