the issue that caused societal collapse in the mouse utopia Behavioral Sink was overpopulation, not that they had their needs met comfortably lol

for a more accurate comparison look at Rat Park Experiment.

TL;DR: rats in solitary confined standard lab testing cages will consume lots of morphine laced water available as an alternative to normal water, rats in a spacious cage with other rats of both sexes and entertainment are not very interested in the morphine laced water. in fact they drank more of the laced water when naloxone, a drug that negates the effects of opioids, was added to it. the implication being that the rats were more interested in sweet water than morphine in good social conditions