Hmm, I was just talking to someone about this issue. Not sure if it would work, but you could purchase galvinized 1/2 inch mesh and put it under your beds.

I used a simlar technique with chicken wire to keep squirrels from digging up my tullip bulbs. Worked well until the chicken wire rusted out, thus the galvinized suggestion. Not sure how long it would last though.

Here is a link that might be useful: Sinfonian's garden adventure.

How tough are these buggers? Having no experience with them, I can't tell if this will work, but I thought to post it anyway. They make a plastic reinforced screen material that we use on our windows and our screened porch in the back of the house. The dogs can jump on the windows and rake their claws down it for as long as they want and it doesn't tear. The squirrels run sideways across our screened porch and don't tear up the mesh either. Didn't know if they used teeth or just claws, but they offer this stuff next to the screens at your big box hardware store.