I understand that mammals produce more carbon dioxide than insects on a gram per gram basis, but why is that? I'm thinking it might be because mammals are warm-blooded, which require more energy consumption. Could it also be due to the fact that insects are less active than mammals? AKA they do less work?
3$\begingroup$ From where do you understand this? Could you provide a source? $\endgroup$– kmmJan 30, 2016 at 18:37
1$\begingroup$ Source and context, please. For example, it doesn't seem likely that a resting mammal will produce more CO2 than an insect running for its life. Could be, though $\endgroup$– telJan 30, 2016 at 22:25
As you said, endothermic animals such as mammmals or birds consume more energy and therefore expelmore CO2 not only because of a higher betabolic rate or to keep warm, but also because they are more active. Even taking all that into account you are missing the biggest difference between them: size. The consumption of energy is not directly related to the size, in fact, the energy requirements drop exponentially with the reduction of size. The same phenomenon explains why they are far stronger, fall-resisting...
1$\begingroup$ The answer seems to be okay, but please provide references to your claims so that people can check and read further. $\endgroup$ Jan 13, 2017 at 14:29
$\begingroup$ oxygen consumption endotherms vs ectotherms advan.physiology.org/content/31/1/97 $\endgroup$– JohnJan 13, 2017 at 15:37