I have no doubt that a cat or a dog, if they were present, would have leaped into the fray and maybe dispatched at least one of the fleeing rats.
Personally I have neither the agility nor the teeth that are necessary for such quick witted killings.
I was surprised to read that rats have such a short lifespan. Most juveniles don't live a year. Even those that make it to full grown only have a life expectancy of 18 months. Yes I know they make up for it by breeding at breakneck speed.
But they certainly need a safe place to do that.
Forecast is for freezing temperatures tonight (finally!). I hope the timing of their exodus from the pile is fatal.