How Long Can Lice Live?
How Long Can Lice Live Without a Host?
Conditions such as temperature, humidity, moisture and availability of food determine how long lice can live.
Head Lice & Pubic Lice
For a lifespan longer than about 8 to 24 hours, head lice and pubic lice need temperatures of 82-86 degrees F, high relative humidity, and an easily obtained source of food (blood.) All of which are conditions closely associated with the human body.
Body lice do not live in constant contact with the human body. Instead they live in the seams and folds of underclothing worn on a person’s body, but they still need to feed on humans in order to survive.
When not able to obtain a blood meal, body lice will usually live only about one week and in harsh environmental conditions, even less time than that.