I think the others are right and that as long as you shut your cats in a confined space they will scratch to try and escape, especially if they have access to the rest of the house during the day. Let them sleep elsewhere as long as they have access to litter trays in the kitchens. They'll probably happily settle down to sleep elsewhere. They probably want a warm sofa or carpet to snuggle down on rather than a hard kitchen floor, especially on a cold winter night. (And wouldn't you?) Cats are no different to humans in this respect. They need a comfortable environment in which to sleep. If they're restless, they won't sleep at all and be destructive, and you won't get a decent night's sleep either. Give in !