ripped up wax at your time of the year sounds like robbing. especially since it's in multiple hives. one hive, and it might be something like a mouse...although those are more common in winter.
reduce entrance size to smallest and make sure there is not feed around that might be drawing yellowjacket, other bees, wasps, etc. also check your hives for queens and make sure you feed them back up. robbing can kill hives, it sure can kill queens, but it also reduces/eliminates stores.
let us know what you find. pics if you want. that always helps.
ask your friend if there are a lot of bees flying around and looking agitated.
if you find really weakened hive, you may need to consider either combining, or trying to overwinter in nucs. don't know what your winter climate is or how close you are to winter?