What do they use and when?
We use old hand towels suspended by hooks over the back of their outside cage. They like to lounge and play in these. Occasionally over the summer on a hot day, I have found one ferret asleep in this hammock.

A hanging napsack - note soft fleecy lining.
We use sleep sacks for their bed area and for indoors. Sleep sacks are like hammocks, but with the flaps folding over the top to make a nice, cosy fleece-lined envelope. They love to sleep in these. I bought one from a shop, but felt it wasn't big enough even for two ferrets. A bolt of creativity hit me, and I made up three larger sleep sacks for the ferrets. It is optional whether they are hung or not. Our ferrets don't sleep in anything else.

The peek a boo hammock from Dreamweezle Ferret Bedding is sturdily constructed.
Ferrets like to be at the front of the cage so they can watch what's going on. Here we've hung a commercially made 'peek a boo' hammock, which went down really well. Tilbury loves this and it is his favourite place now. What's good about it is that they can go to sleep and feel secure as they're hidden, or they can lounge securely with just their head peeking out. A fabulous idea - available from Ferrets About.

How to make a budget deluxe ferret hammock.
After seeing how much the ferrets like this hammock, we decided we could make a budget version, which so far is going down well too. Go to a charity shop or a jumble sale (much cheaper - fleece tops for 20p!). If there's a zip, zip it up. Cut off the sleeves - this allows ferrets to stick their heads out of the arm holes. If there are pockets cut holes in those - this allows ferrets to stick head out of holes or allows access inside the top. Finally snip a small hole in each corner - you won't need to sew anything as fleece doesn't fray and is quite strong. Thread some string through the holes and hang. Voila. if the adult size is too large, then look out for a child sized fleece!