So I was thinking about Rahi and the Matoran Universe, and how they're a part of the MU's artificial ecosystem. And then I thought about how Matoran are really important for Mata Nui's health, and so the GBs/Mata Nui would surely want them to be working smoothly and without much bother.
Of course, if they die, or are damaged, there are systems to solve that (Red Star, Karzahni), but ideally they shouldn't really be needed much.
So I was just wondering, why did the Makuta make such nasty Rahi that would more than occasionally attack Matoran/sentient species?
I'm not talking about Teridax on the island of Mata Nui, since the Makuta were already "evil" by that point, and Rahi like Visorak which were basically mass production weapons for the Brotherhood. I mean when the Makuta were new, not considered evil, given the job of making animals that would help (my theory now) maintain some kind of "Protodermis Cycle" (sort of comparable to the carbon/nitrogen cycles on Earth). Did they then also think "Hey, let's make these Rahi prone to attacking the workers who do the important stuff that needs higher sentient intelligence to do in our synthetic ecosystem, because that will surely help too".
Were Rahi always meant to be aggressive to Sent. Species? Sure it was never a huge problem, there wasn't really ever a significant loss of life (I wonder if the Kanohi Dragon/Tahtorak/First Rahi may have been exceptions) but surely dangerous Rahi could only have been bad for sent. species?
So yeah, why did the pre-evil Makuta make Rahi that would kill Matoran?