I have a small number of african soft furs in a tank. The water bottle I had that hung on the lip of the tank was chewed apart by the rats. I found an all glass one at a local pet store, but it is designed for wire cages. Any suggestions on who makes one with no plastic, and where I can get it? Also, I have alfalfa blocks for them to chew in addition to their regular food. They seemed to prefer the plastic water bottle to the alfalfa blocks. Any suggestions on what might work better for them?