We had a sleeper sofa for years with our ferrets. I stapled an old sheet on the bottom to prevent the ferrets from getting inside of it that way. They had made their way into the arms and would dig out the foam stuffing so I was also concerned about one of them eating the foam when I fixed it. If you use a staple gun, you can easily attached the sheet so the ferrets can't pull it loose. We did have one accident involving the sofa and a ferret when my husband lifted it so I could retrieve a toy. We thought all the ferrets were out to the room. When he set the end of the sofa back down, Socks was under it. One of the metal sides of the sleeper part came down on his neck, breaking it and killing him. Needless to say my husband was totally devastated. We learned the hard way not to just "think" about ferrets but to actually check it out when they are in question! Jane [Posted in FML 5866]