Since I am going to set aside a special area for my "wabbits" I can determine the enviorment . It seems that they will tolerate the kind of cold that we get in Northern AZ but there is more . I intend to grow worms in the manure pits to be kept under the cages . Worms are happy (and PRODUCTIVE) at 70 -75 degrees .I have read on this very informative forum that rabbits tend to "shut down" at 85 degrees . So the question begs . What temp. has been found to be best for the rabbits ? We'll see if we can't come up with some kind of climate that will serve both . My entire project is with a symbionic goal in mind . In order for one to be worth the effort both must perform . Between the mats you might see in a commercial greenhouse that have thermostats and a solar exhaust fan I might be able to keep one temp at the bottom and another at the top providing the spread is not too much . If it matters we are talking Californians and or New Zealands . The worms in question (thank you for asking) will be European Nightcrawlers .They will be for sale to fishers and also will work in the garden and greenhouse .Thank you in advance for your time in this matter .