Show fleas carry germs fleas carry germs typhoid fever and bubonic plague but these two INS ills particularly bubonic plague are their most rn ost potent threats it was centuries before man mail discovered the plague was transmitted by fleas however and before the discovery the black death wiped out halt half Eu ropes population in one year in 1907 the indian plague commission commis finally proved fleas flea s carried the plague the proof was simple cages containing rats were hung at different levels above fleas the fleas could hop to the lower cages reach the higher ones and all the rats in the lower cages died of the plague |