Delilah has escaped twice, and was found in the same room as her cage both times... first time she was squeezed behind the dresser, plastered against the wall & wrapped in wires. Second time she was on TOP of a very tall bookshelf, just comfortably curled in a ball - so yes, they can "climb" rather high. As the others have suggested, look anywhere that is warm and tight, especially near electronic equipment (Toby loves hanging near my laptop and DVR/TV). There's also the flour trick that was mentioned, and you can lay crinkly paper or tin foil around the house... then keep your ears open when it gets dark, since they tend to move around at night. Good luck!!!