kangaroos have amongst the smallest brains Compare Brain and Body Sizes (has pics and statistics of animal brains and sizes) Brain and Body Size compare the size of brains http://serendip.brynmawr.edu/bb/kinser/Size1.html http://serendip.brynmawr.edu/bb/kinser/Size1.html brain size and body size source Brains and Body-Size http://serendip.brynmawr.edu/bb/kinser/Size1.html source