Group housing and nest building only slightly ameliorate the cold stress of typical housing in female C57BL/6J mice.

Huddling and nest building are two methods of behavioral thermoregulation used by mice under cold stress. In the laboratory, mice are typically housed at an ambient temperature (Ta) of 20°C, well below the lower end of their thermoneutral zone. We tested the hypothesis that the thermoregulatory benefits of huddling and nest building at a Ta of 20°C would ameliorate this cold stress compared with being singly housed at 20°C as assessed by heart rate (HR), blood pressure (BP), triiodothyronine (T3), brown adipose (BAT) expression of Elovl3 mRNA, and BAT lipid content.