I guess you'd have to know how big a fly's brain is to begin with, then figure the brain to weighhttp://en.wikipedia.org/wiki/Brain-to-body_mass_ratiot ratio and compare that to a human, The article says you can't figure a creatures intelligence of the brain to body weight ratio.
4 months ago
Last edited at 1:28PM on 12/3/2013
You should look at the body to brain ratio. I don't have a number exactly for flies but the ratio for insects is usually bigger than human. The largest would be small ants with more than five times the ratio. The ratio is 1:40 for average human. So I would assume it would be something like 1:10 or more. So it would make something like 5 kg or more.