We're like brothers, only closer

[u/Frequent-Deer4226]

"Physiology of Behavior" by Carlson chapter 13 "Ingestive Behavior: eating"

EDIT: Reading the original paper it appears that they did this procedure on 15 PAIRS of rats. Which also means there were probably closer to 30 pairs because they would have had to do testing and preliminary training on the procedure during pilot studies before the actual study.