I've got one cage here with two girls, Misty and Tilly, and I CANNOT have fleece in this cage and expect it to last more than a week. They don't ingest it, but they do like to get inside the hammocks. I don't buy hammocks for them anymore, they get theirs made by me - because I'd spend a fortune keeping them in hammocks.
The others have hammocks and pillows. Some use them, some don't.