We have had five ferrets in a Ferret Midwest Playpen for the past year. We did modify the cage, but only added space. How we placed the hammocks were to prevent a ferret falling, and going to the bottom of the cage. Sometimes they do go all the way down, but fall into a hammock first. I think, IMO, the owner just needed to be educated on ferret care is all. You making the time to contact the person often can really help them to change the way they think.. Example: I tried to rescue a ferret for 6 months. I told them of ferret care once, gave their kids hand written notes off and on for 6 months. Then the family asked me to take the ferret which we did. How happy I was. Even tho we had to wait 6 months, I kept up on trying to rescue this ferret with letters and talks to the owner. PLEASE, don't give up trying... Debbie [Posted in FML issue 2959]