" At Stone’s direction, Harry removed ovaries, blinded the female rats, and removed their olfactory bulbs. Sightless, hormone-deprived—it didn’t matter. The mother rats crawled determinedly toward the baby rats. They were slower, maybe, but the homing instinct was magnetic, needle to the north. "

― Deborah Blum , Love at Goon Park: Harry Harlow and the Science of Affection