 Additionally , the DNA differences between head lice and body lice provide corroborating evidence that humans used clothing between 80 @,@ 000 and 170 @,@ 000 years ago , before leaving Africa . Human head and body lice occupy distinct ecological zones : head lice live and feed on the scalp , while body lice live on clothing and feed on the body . Because body lice require clothing to survive , the divergence of head and body lice from their common ancestor provides an estimate of the date of introduction of clothing in human evolutionary history . 
