How did the rats get the black death and not die?

Answer 1

They did die. After they were infected by the fleas that were the original carriers, they got sick. They transmitted the virus inadvertantly through the food they nibbled off of in humans' pantries. Humans would eat this food and get infected with the black plague. Towards the end of their lives, as the virus progressed, the rats would go a tad loopy and bite humans, therefore directly transferring the virus to humans. The rats then died. Other creatures would feast on the rat's corpse and be infected. The cycle continued.

Answer 2

No medical knowledge existed in Medieval Europe to cope with the disease. In fact, Europeans didn't know that rats were behind the black plague. Trading ships accidentally brought the black rat from India and Central Asia to Egypt, the black rats caught these germs and, not being adapted to them, died of the plague. Then the fleas jumped on humans. Lots of rats died but they reproduced so quickly that the plague didn't effect the rat population as drastically as the human population.

Answer 3

Evidence suggests that lack of heaping rat carcasses from the middle ages implies they may have been carriers without actually getting sick.