How stable is your vivarium's temperature? Fluctuations in vivarium temperature significantly impact metabolism and behavior impeding scientific reproducibility

•Vivarium temperature (temp) fluctuates on a monthly, daily, and even hourly basis.•Fluctuations in vivarium temp impedes scientific reproducibility.•5ºC ∆ in vivarium temp impacts total and resting energy expenditure 27–39%.•5ºC ∆ in vivarium temp impacts physical activity, food intake and sleep 13–50%.