This question already has an answer here:

I want some giant insect-like creatures for my setting. Since there are already answers here that say simply scaling up insects isn't feasible due to things like their circulatory system, let's assume that our big insects have the proper organs and internal piping to handle being big.

Does a creature with an exoskeleton have a lower size ceiling than one with an endoskeleton before the square-cube law becomes an issue? Can I make giant bugs at a similar size to giant mammals, assuming they have the proper internal organs?


marked as duplicate by kingledion, sphennings, Community Apr 27 '17 at 14:00

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ Should be ok, they would have to shed their skins periodically though and I think that is going to be a major problem. $\endgroup$ – Kilisi Apr 27 '17 at 9:26
  • $\begingroup$ @Mołot Not a duplicate because that question says they can't get very big because of their internal organs, whereas my question specifically avoids that problem $\endgroup$ – Pyritie Apr 27 '17 at 9:34
  • 1
    $\begingroup$ @Pyritie There are answers to the proposed duplicate which address the mechanical inefficiency of the exoskeleton itself, separate from circulatory issues. After reviewing that post, I believe this is a duplicate. $\endgroup$ – kingledion Apr 27 '17 at 13:45
  • $\begingroup$ @kingledion Thanks, I missed those other answers the first time I read it. $\endgroup$ – Pyritie Apr 27 '17 at 14:00

They should be able to be that big. But your major problem then is how did they get that big.

They either start that size after coming from a grub which would need to be a lot bigger, or they somehow grow in which case they need to shed their rigid skins periodically which would leave them extremely vulnerable.

There are a few ways insects grow, here is a link explaining it in basic easy to understand terms Link

Another major issue is what this creature eats, insects lay a LOT of eggs, imagine 1000 elephant size caterpillars, they will transform the landscape and decimate forests. Some caterpillars grow 1000 times in size and eat 27,000 times their own body weight before they cocoon themselves and begin their transformation.

Mammalian elephants already have a huge impact on flora, but don't breed in such numbers so it's not the same.

One way to solve this would be to have insectoids that do their larval stage in the sea, or lakes, then come to land after completing their changes. if they were anything like dragon fly larva they'd make awesome sea monsters in that stage of their lives.

  • $\begingroup$ Is there a problem with the grub being a lot bigger? $\endgroup$ – Pyritie Apr 27 '17 at 9:35
  • $\begingroup$ Yes, what does it eat? Forests? Elephants? $\endgroup$ – Kilisi Apr 27 '17 at 9:37

Not the answer you're looking for? Browse other questions tagged or ask your own question.