Question: who has the largest brain in comparison to its size
Answer: Species Brain : body mass ratio ( E : S ) small ants 1 : 7 tree shrew 1 : 10 small birds 1 : 14 mouse 1 : 40 human 1 : 50 cat 1 : 110 dog 1 : 125 squirrel 1 : 150 frog 1 : 172 lion 1 : 550 elephant 1 : 560 horse 1 : 600 shark 1 : 2496 hippopotamus 1 : 2789