Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
People were trying to find the rare butterfly, and the young protagonist figured out that the centipedes were the larvae of the butterfly.
I suspect this is either A.M. Lightner's Doctor to the Galaxy or The Space Plague. I know one had to do with butterflies - I read them 45 or so years ago - but info on them online is meagre.
Required, but never shown