Ok, so I surrounded my base in the highest tier stone walls (stage 5), however ive been noticing that lately that when I leave my base and return, most of my walls seem to downgrade to stage 3 walls, with only like two stage 5 walls left. I dont think my base could have been attacked as I was not near it, so monsters wouldnt really go near the walls. Has anyone else has this problem, and if so can you tell me whats wrong? I hate to waste rocks building walls that wont last. Although now I just set off a shit ton of slime explosions in the caves to farm rocks, works like a charm =).