The flies sometimes don't stick well on them and escape. They are smaller in size (almost half) compared to other similar ones that I randomly found in a supermarket, but more expensive. And the "cherry on top" of this mediocre "cake" is that they don't even provide the little wires with which you hang them (at least the first one I opened had nothing inside), wires that the cheaper and larger ones from the supermarket have. So it's better to go for a walk to the Super Market.