>>12879373Arthropods have trachea systems, no lungs nor gills. There fore they do not have blood. Due to this inefficient system, their body size is limited by the rate of diffusion and by extention the oxygen contentration of the atmosphere. At its current level it doesent allow for large bodys and there fore they can not have large brains. At this point, the R type reproductive strategy and inherited behavioral patterns are more efficiet, and there fore their relative barin size shrinkes even further.
There were at one point about 300 million years ago giant insects, those could have been smarter, though i know of no proof for them having larger relative brain sizes.
