The smaller of my two clown loaches does something strange. It zooms around the bottom of the tank with its nose/snout to the glass. I'm talking about hyper speed...mach 10. There are things on the bottom of the tank, like rocks and things, so the loach bumps into them, but it keeps on going. Is it getting hurt? What is it doing? I tried to examine the head to see if there were scratches...I'm sure there are some, but I don't see any outright bleeding.