Protectors were actually afraid of Puppeteers, as well. They knew that they could pose threat to their species and, given the chance, would have wiped them out. That factored into
Ringworld Throne to a significant degree. That was part of what the "Brennan Monster" was doing in fighting the Protectors. He didn't want anything to happen to Humans, but he saw other species as potentially beneficial to man, too. They didn't know about any other species yet (Phssthpok was the first alien they'd encountered as of the novel
Protector) but once Brennan was changed he would have been able to reason out the existence of other species.
My favorite thing about the Ringworld books is probably the true story where Niven explained why he wrote the second book,
Ringworld Engineers. He got emails from all over picking at the engineering of his original concept, including one from Freeman Dyson himself! He also tells the story of being at a convention in Boston and having an entire engineering class from MIT start chanting during his speech "the Ringworld is unstable" over and over. They'd done a semester examining the whole thing. He had to incorporate all of this into the second novel to fix the things he'd overlooked in the first one. That's where the attitude jets came from, for example.
Stories like that are why I enjoy the mega collections of Niven's stuff, the one with the essay "Bigger than Worlds,"
Playgrounds of the Mind, and the other one,
N-Space. They contain some short stories, some excerpts from the big novels, some essays (including Man of Steel, Woman of Kleenex) but also lots of little stories. The one about "Speaker to Seafood" is a riot.
I met Larry Niven at a SF convention several years ago and spent the whole weekend with him and Jerry Pournelle in the hospitality suite getting drunk. Pournelle and I knew each other from years of attending the same computer conventions, so he let me into the inner circle, even though it was my first SF con. Very fun people. I even got to discuss with him some flaws I saw in the back story for
Protector, where his supposed biological link just doesn't stand up to what we know now scientifically about our species and other species on Earth. I provided him an alternative biological explanation for the similarities between humans and Protectors, that even added in a connection back to the Slaver/Tnuctip galaxy wide war he alludes to in his other Known Space stories. To explain why the "wrong" version of the story was in the book
Protector I told him he could simply say that Brennan, the only source of the info in the novel, had lied to protect humans from knowing the truth, which would mess with their natural development. He's never used it, but he told me he liked it.
Oh, and the Tnuctip created the sunflowers for their masters, the Slavers. The Tnuctip were master genetic engineers whom the Slavers controlled with their mental powers, that is until the Tnuctip rebelled and the Slavers wiped out all intelligent life everywhere in the galaxy, including themselves, by unleashing their super weapon. That was several billion years ago, however. We came along later.