Brown adipocytes have a more limited distribution in the body than white adipocytes, contain several small lipid droplets (multilocular appearance), and oxidize fatty acids for heat production.
In mouse brown adipose depot is present throughout life, and in humans is present at birth and its volume is reduced in adults. Brown fat can easily be identified at birth in both rodents and humans, in particular in the interscapular region, where it is innervated by the sympathetic nervous system.