11 ms·

I doubt after week 1 that there were only 16-20 rats. Those things reproduce exponentially if left with space/food/mates.

• loup-vaillant 13y ago
  If it's because of some genetic immunity to drug addiction, the children are likely to benefit as well.
  • tomjen3 13y ago
    The rats that were made addicted to the heroin did experience minor withdrawl symptoms so they are able to get addicted.
    • duaneb 13y ago
      Withdrawal is a symptom of physical dependence, not addiction (which is harder to define/identify).