The best kids films in the 80s ?

From what I remember of the story:
Some doctor studying behavior created a rat haven. He had observed rats in studies for so many years that he noticed certain recurring behavior patterns. He constructed a massive "perfect" rat environment. Huge rooms lined with plenty of feeding/drinking apparatuses and multiple comfortable nooks. He used his years of experience to inspire his efforts at supplying them with all things loved and needed by rats. Soft nesting material, ample room for expansion, lots of hiding places, limitless food, etc. The ultimate results were disturbing and disastrous. It turned into a schism pinata. Their paradise became a murder hole with a wide variety of bad behavior rife among the population. He tried two times, making adjustments each time. Same results. (this is all by memory so I may be editorializing subconsciously)

I wish I could remember the doctor's name or what O'Brien's connection to him was.

..... and then I looked it up. Why didn't I start with looking it up?
Here:
https://www.atlasobscura.com/articles/the-doomed-mouse-utopia-that-inspired-the-rats-of-nimh