I have 5 buttons total. Split into two large guinea pig cages. Ive had them since oct of last year. For the first month everything was fine. I didn't even change the pine shaving bedding that entire month. At the start of month 2 i changed the bedding replacing it with aspen. It's just what I happened to have on hand. By the next day there was a noticable oder. Noticable but not overpowering. At this point I was using open water dishes on the floor. About 2 weeks into the aspen i purchased tube waterers with a narrow trough for drinking and changed the bedding again but sticking with the aspen this time. Well the oder became increasingly strong. I decided to get rid of the aspen and go back to pine. The pine was flakeyer and finer in contrast to the aspen which was big chunkey and curly. I assumed the less absorbant aspen was the culprit of the smell. I was wrong. The smell continued to get worse and this last time i replaced the bedding I placed my usual generous 2-3 inches of shavings on top of a good amount of baking soda spead out over the plastic base. The baking soda did nothing. The smell is still so strong. It hits you in the face when you open the door to the room and smells like a filthy chicken coop, the kind with 10 inches of feces built up. I have them set ontop of glass jars flipped upside down to keep the troughs above the shavings. When i do change the bedding the shavings under the jars are damp and do have a bit of a mildew oder. But its not at all the same smell as the dirty coop smell and the dampness is only directly under the glass jars. The tubes don't seem to be leaking but the only other explanation for the damp shavings is the qail are spilling. I'm at a bit of a loss and I'm not even sure the tube waterers are the problem. Food is no where near the water and i just cleaned the cages Wednesday and the room is already back to that awful smell.