1. A method for electronically determining a metabolic characteristic of an experimental animal in a living space, the method comprising: confirming that a temperature in a living space is within a predefined range that consists of temperatures near or within a metabolic thermoneutral zone of the experimental animal; capturing at least one infrared image of at least one experimental animal in a band of infrared radiation that is within the range of from about 3 μm to about 14 μm in wavelength; identifying at least one data set of the at least one infrared image that corresponds to a tail of the experimental animal; processing the at least one data set of the at least one infrared image to evaluate a temperature of the tail of the experimental animal; and determining the metabolic characteristic based at least in part on the evaluated tail temperature.