Hello Moxie, We had this problem early on in ferret years-- so we did the following. Purchased a cotton polyester flat bed sheet - flipped the box spring over - used a commercial staple gun and stapled the bed sheet while pulling it taught-- all the way around placing staples close enough together so little ones couldn't pull on the sheeting. It has saved us considerable worry and fret! Hope this helps! Alicia from the pre Ferret Wise days! [Posted in FML issue 3027]