I came home from work and saw that my Green-winged Macaw, Ruby, was trying out her new Punk Parrot look. She had undone the quick link I had been using and had gotten it stuck around and in her beak. She had smashed it so flat and tight against the bottom part of her beak that neither she nor I could get it off. I had to use bolt cutters to break the link to free her. It scared both of us. I changed all my toy hangers to these. She cannot unscrew these. I love these things!