Introduction. What is a small mammal? ; Advantages and disadvantages of being a small mammal ; The protagonists (Monotremes and marsupials ; Afrosoricida, Erinaceomorpha, Soricomorpha, Macroscelidea, Scandentia, and Dermoptera ; Chiroptera ; Primates ; Carnivora ; Rodentia ; Lagomorpha ; Hyracoidea) -- Modes of feeding. Insectivory (General characteristics ; Terrestrial insectivores ; Arboreal insectivores ; Semiaquatic and fossorial insectivores ; Subterranean insectivores ; Aerial insectivores) ; Herbivory (General characteristics ; Granivores ; Frugivores ; Nectarivores ; Gummivores ; Folivores ; Case study) ; Carnivory (General characteristics ; Flesh-eating carnivores ; Piscivores ; Sanguinivores) ; Omnivory (Omnivorous carnivores ; Mycophagy ; Case studies) -- Environmental adaptations. Endothermy ; Heterothermy (Torpor ; Hibernation) ; Coping with cold (Insulatory changes ; Countercurrent heat exchange : the miraculous net ; Reduced level of activity ; Reduction of body mass [Dehnel’s phenomenon] ; Fat tails ; Social thermoregulation ; Increased heat production) ; Coping with heat and aridity (Conserving water ; Dietary water intake ; Evaporative cooling ; Pelage insulation ; Behavioral avoidance of heat) ; Ecogeographic rules (Modified size of appendages [Allen’s rule] ; Seasonal color dimorphism [Gloger’s rule] ; Body mass and latitude [Bergmann’s rule] ; Case studies) -- Reproduction. Reproductive variations (Delayed fertilization ; Delayed implantation ; Delayed development ; Embryonc diapause} ; Mating systems and reproductive strategies (High fecundity ; Monogamy, housekeeping, and mate guarding ; Absentee maternal care ; Lek behavior ; Eusociality ; Semelparity : Breeding and sudden death) ; Population cycles : lemmings and snowshoe hares.