When it comes to the spread of the plague, rats and fleas usually shoulder most of the blame. But lice may have been just as responsible for transmitting the disease, according to a new study.When it comes to the spread of the plague, rats and fleas usually shoulder most of the blame. But lice may have been just as responsible for transmitting the disease, according to a new study. When it comes to the spread of the plague, rats and fleas usually shoulder most of the blame. But lice may have been just as responsible for transmitting the disease, according to a new study. Science & tech Articles | Mail Online