Silver Mountain Vole 
Slender squirrel 
Smiths Bush Squirrel 
South African springhare 
Southern Amazon red squirrel 
Southern cotton rat 
Southern flying squirrel 
Southern red-backed vole 
Southern viscacha 
Striped ground squirrel 
Sumichrasts vesper rat 
Sunda porcupine 
Thirteen-lined ground squirrel 
Townsends chipmunk 
Tuffted pygmy squirrel 
Uinta chipmunk 
Uinta ground squirrel 
Unstriped Ground Squirrel 
Variegated squirrel 
Webbs tufted-tailed rat 
Western dwarf squirrel 
Western Gray Squirrel 
Western nesomys 
White-footed mouse