I bought a plastic stone looking cave for my betta "Guppy", the kind with holes in the bottom that fill with water to make it sink. For a few days there were times I could NOT FIND him. He is in a 10 gallon with a small ramshorn snail and I swore Guppy jumped out and died I looked everywhere. He appeared after I left and came back. I noticed his fins have been ripped getting worse everyday. I couldn't find him again today so I made noise like it's feeding time and just sat there and waited. He was squeezing into the bottom hole of the plastic rock.. I had no idea they could get in such tight places. So relieved I just hope his beautiful fins grow back soon.