You can use ropes to hang them. It is also possible to buy a commercial hammock. These are made from canvas and have hooks for hanging. They are sold as ferret hammocks and may be quite expensive. They may still be destroyed.
Wheels are excellent toys for both mice and rats.
Mice in particular adore them. They provide excellent physical exercise. The main problem with wheels in Australia is that they are not very mouse or rat friendly. Most rat and mouse clubs recommend running wheels should have a flat running surface as this reduces the chance of a rat or mouse breaking a toe, leg or tail. I have not seen any wheels in Australia, which do not have rungs.