They used bottle jacks on ours. Lifted the cages right out of the ground. A bag of concrete on each leg. I’m going with cameras and a portable livestock electric net fence strung like a tent, just inside the stockade fencing. If they jump or climb the fence, they will land in an electrified net and won’t be able to get out of it. A 6000 volt pulse every one second will keep them incapacitated.