Speaker-to-Animals only posted once, in 2001, for about 13 minutes.
I’ve been trying to hatch up an explanation that covers a couple of things, but so far unsuccessful.
The Home-ian protectors were all childless, remember, because their breeders had been killed in the virus infection that Truesdale brought to Home. Being childless, they could cooperate “for the good of the species”. That’s why they could get together as an army and fight the Pak fleet.
They were also cleverer than the Pak-born protectors, Niven said. So maybe they were so clever that they successfully designed a time travel widget. They went back in time and designed and built the Ringworld so that hominid breeders could have a massive kingdom to roam and breed free from the constant war that devastated Pak.
My reasoning breaks down when it comes time for them to populate the Ringworld with hominid breeders.
Oh, look! Here’s Speaker-to-Animals!
Kzinti are NOT cute!
(Although they do like to have their ears scratched!)