In study 65 degrees seems to be the "optimum temperature" for breeding. In my personal tests 15 degrees above and below this (50-80 degrees) and they do just fine with limited degregation in breeding.Originally Posted by CntrlF8
Beyond this:
Too cool and the rats almost completely stop breeding...I too keep mine in the garage and during the winter months I run a space heater to keep the temp at 55+...when I didn't they all buy stopped producing and those that did had very small litters and the babies were undersized.
Above 80 - you start to get more deaths, more water consumption (by triple) which leads to more urine and faster build-up of ammonia necessitating sooner cleanings. Also any lapse in water at these higher temps and the babies don't seem to survive more than a couple of hours.
These are just my findings so they may vary from what others see.