Physical factors
Mice have a relatively large surface area per gram of body weight. This makes them sensitive to large fluctuations in ambient temperature. Nude mice (see picture and movie), but also pups, sick animals and those who have undergone surgery, have a strong preference for slightly elevated ambient temperatures and for nesting material that offers protection.
Humidity and ventilation
Animals are also sensitive to large fluctuations in humidity and frequency of ventilation, which are associated with respiratory problems. Extremes of high and low ambient air humidity, and rapid changes thereof, are to be avoided.
Ultrasound sensitivity
In addition, mice are very sensitive to high frequency sound (ultrasound). Electronic equipment, which can generate this type of noise, operating in animal rooms has to be avoided, especially while the animals are resting.