did you leave some tempting treat in your pack? hungry rodents don't use zippers!
One chewed a hole right through my platypus water bladder draining my water supply, the very first time I climbed CC. My bag was empty before even starting the climb. I made damn sure they couldn't get to my pack my second time on it.
Next time invest in some strychnine weenies. Just leave them out by your pack.
But what if some climbers' think they are booty weenies?
Then you get their gear.