I have a DSB and really like it. So do the fish. They have dug tunnels under everything. They are constantly digging with their tails, especially the damsels. They also carry small rocks and shells from one place to another. I have a clay pot thats been in there for years and i saw a damsel carrying stuff into it the other day. I've witnessed the clarkiis do it as well. Anybody else seen this behavior?