Never, EVER, mix the genes of humans and rats:
I have just learned a very interesting tidbit about the reproductive biology of rats.
The male rat, unlike the human rat, sorry, the human male, serves two purposes when copulating with those fabulously sexy females the rat species has going on.
The act of copulation both makes a present of his sperm and stimulates the necessary "bits" within the female to poduce the hormonal secretions necessary to fertelize the eggs, and therefore propagate the numbers challenged rat species.
The interesting part in all this is what some of you might have been very quick to pick up on - if the male rat prematurely ejaculates the whole gig is up. No fertilisation, hence no little baby rats to give all those cities their raging rodent nightlives.
All i can say is that thank Christ all mighty that the human rat, sorry, human male is not counted on to prime the hormonal secretions of anything.
Who would need nukes if that scenario were ever to turn into a reality?
Note to scientists: In the name of all that is holy - keep the genetic materials of humans and rats well seperated. Which of you would want to make an already appalling situation (right ladies?) any f**cking worse.