safe cage toys???

I was just wondering if anyone else had this idea or had tried it. our ferret likes loves little balls with bells in them he also really likes shoe laces so we had this great idea to thread the shoe lace through the ball and play with him with it that way and he loves it!!!! so then we had the idea that we could hang them from the top of his cage and let them dangle for him to play with. but we are a little bit worried that he might get tangled in it or something what do you guys think???

I've seen a few cages with the same toy.  I haven't heard of any safety issues.

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