Question: What animal has the biggest brain relative to its body size?
Answer: A tiny genus of ant has the largest brain for its body size. Brachymyrmex has an average body mass of up to 0.049 milligrams and an average brain mass of 0.006 milligrams. That means its brain is roughly 12% of its body mass, giving it a brain-to-body-mass ratio of about 1:8. Human brains weigh about three pounds, and so the ratio, depending on the individual, can be 1:50 or higher.
