I live in north Fl. and keep both T.c.bauri and T.c.major in outdoor enclosures year round. They are in a 12'x5'x6' enclosure split in half. I use concrete mixing tubs for soaking and during winter I simply bag my grass clippings a few weeks before and pile them in an area where the turtle will burrow into when its to cold for them. Usually a pile 12" thick, I've never had a problem even during night freezes. Nor have I had a problem with fire ants and I have adults and juveniles (4-5" outside. I definately recommend a top to keep turtles in and raccoons out, Ive lost turtles to raccoons before; not fun finding a headless turtle. Hope this helps