The Piper books are Little Fuzzy, Fuzzy Sapiens and Fuzzies and Other People (in that order). I like where Tuning went after Fuzzy Sapiens better than where Piper went. Fuzzies and Other People turns on Fuzzies being so innocent and primitive that they don't know how to lie. Tuning actually addresses where Fuzzies come from and the fact that it makes no sense for them to have evolved to require a nutrient that's incredibly rare on Zarathustra.