Snopes says this one is unverified, but you gotta admit, it's not inconceivable. I've gone into offices in downtown areas where there were loads of mice, where going to the network wiring closet was an "iffy proposition". One guy in one place told me that they couldn't keep creamers around for their coffee, because the mice learned to chew through the top to get at the liquid inside. No word whether they required the true cream or whether the non-dairy creamer was sufficient.
My last workplace was infested with rats and weasels.