Does anyone have ideas on how to adjudicate the damage that burrowing creatures do to objects? For example, the Thoqqua can burrow through rock at 20ft speed. According to DMG p.107, a 10x10ft (x5 ft thick) section of unworked stone has a hardness 8 and 900 hit points -- and the Thoqqua should be able to go through 4 of those in a single move. How would translate that into general damage? Suppose a Thoqqua tried to burrow through hewn stone? Masonry? Adamantite? How quickly could it burrow through, if at all? Suggestions?