Science Fiction Meets Reality
According to The New York Times:
This sounds like Mother Hittons Littul Kittons
The other colony of rats has been bred from exactly the same stock, but for aggressiveness instead. These animals are ferocious. When a visitor appears, the rats hurl themselves screaming toward their bars.
“The ferocious rats cannot be handled,” Mr. Albert said. “They will not tolerate it. They go totally crazy if you try to pick them up.”
When the aggressive rats have to be moved, Mr. Albert places two cages side by side with the doors open and lets the rats change cages by themselves. He is taking care that they do not escape to the sewers of Leipzig, he said.
I don't know if C'Mell is next …
She moved among them. She and her father had bred them from Earth mink, from the fiercest, smallest, craziest little minks that had ever been shipped out from Manhome. The lives of the minks had been shaped to keep away other predators who might bother the sheep on whom the stroon grew. But these minks were born mad.
Generations of them had been bred psychotic to the bone. They lived only to die and they died so that they could stay alive. These were the kittons of Norstrilia. Animals in whom fear, rage, hunger, and sex were utterly intermixed; who could eat themselves or each other; who could eat their young, or people, or anything organic; animals who screamed with murder-lust when they felt love; animals born to loathe themselves with a fierce and livid hate and who survived only because their waking moments were spent on couches, strapped tight, claw by claw, so that they could not hurt each other or themselves. Mother Hitton let them waken only a few moments in each lifetime. They bred and killed. She wakened them only two at a time.