The Fruit Fly Ninja is the most effective solution against fruit flies. The Ninja resembles a feeding and breeding site for fruit flies, which is why they crawl in quickly but no longer come out. The attractant is of natural origin, contains only food and is therefore completely non-toxic. The Ninja can be attached from the field of view and near the area in question with the rear tape. The Fruit Fly Ninja works for up to three weeks after opening. The Fruit Fly Ninja is the most effective solution against fruit flies (Drosophila), but it does not catch fungus gnats (Sciaridae). If you see small black flies mainly in the indoor plants, then they are probably fungus gnats and no fruit flies.