Dead skin cells are a main ingredient in household dust.

According to a Johns Hopkins research team, 250,000 deaths in the United States are caused by medical error each year. This makes medical error the third leading cause of death in the country.

In Ancient Egypt, people put a dead mouse in their mouth if they had a toothache, according to Nathan Belofsky’s book Strange Medicine: A Shocking History of Real Medical Practices Through the Ages. Mice were also used as a warts remedy in Elizabethan England.