The disadvantage of such a trap is probably the hall of the fishing line. When the bird pulls the line, it bends almost at a right angle and breaks at the bend. After a while, the line needs to be replaced. I propose a design that eliminates this problem. The service life of the fishing line increases significantly, the fishing line does not break anymore. Parts are printed on a 3D printer that almost everyone has. Wire spring (how to harden an ordinary wire so that it becomes springy, see the net). If necessary, I can send files with a 3D model of parts for the printer. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MfehFNzuxLI.html