Ignorance in hygiene and basic medical knowledge affected all classes from King to peasants. The Black Death also affected living conditions making death an ongoing occurrence. Rapid spread of the black death in medieval cities such as London, Paris and Florence was due to the faint thought of planning and heath conditions. choice of sheather was also contributing as people lived in small houses and in country villages, families would be joined by their livestock, resulting in once one member would become ill, it was highly likely that the other members would become ill as well. As houses were build mainly with straw this allowed rats, fleas and other animals carrying the plague it allowed easy access to flourish. Life expectancy was deteriorated as the black death killed a quarter of all babies within the first year of birth, less that half would reach the age of ten and people who passed the age of 10 had a equitable of living till the age of 40.