Ferrets love hammocks. You can buy this little ferret hammock thing that was actually designed for ferrets. The ferret hammock hangs from the top of the cage and they just love it. They can jump in and out and swinging all night long!
You can make hanging ferret hammock with the leg from a pair of jeans. The larger (wider) the leg, the more ferrets will fit to the hammock. All you have to do is buy four pieces of some very thin chain from a hardware store, and eight clips (like the kind used for cheap dog leashes) to connect the jean leg to the ferret’s cage. If you don’t know what kind of clips/chains to get, look at the ones with the ferret hammock at a pet store. Just cut four holes in the jeans (you can put in grommets in if you want) and put the chain through. Hook that end of the chain to itself, and the other end to the ferret cage, and then do that with the other 3 chains.
It’s cheap and easy to replace. If the jean leg wears out, just take it off and attach another one. You could also slit the leg, and make it a hammock instead of a hanging tunnel. It’s even easier if you already have a worn out old ferret hammock just the chains that came with it.
And even easier ferret hammock is to take an old T-Shirt and the metal shower curtain hangers (the ones that close completely) and just poke holes in the four corners. First 10 ferret easy (if the cage will hold that much weight!) and they like to get in between the layers (just watch that nobody gets trapped between the layers).
You can also make one by sewing cords to all four corners of a hand towel and hung it from the ceiling of the cage. I laughed the first time I saw a ferret hammock in a catalog, but believe me, they really do love them!