How long can nits and lice survive off of a head?

Not very long. They need human hair to survive.
For ever. Combing alone e it help but dose not for sure clean it up, use the recommended shampoo, for the whole family, clean all the bed sheets sand if you have bets also do it for them.

Related Questions

How long do head lice generally live?

1-2 days off host. Head lice cannot survive for more than a day or two without a blood meal. Read more...
Head Lice. The life span of an adult louse on a host ranges up to 30 days. During this time, the female head louse can deposit about 90 eggs. After incubating for seven to 10 days, the nits hatch and, after another 10 days, mature into adult head lice and the cycle begins again. Off the host, adult head lice can live about two to four days at 74 degrees fahrenheit (f) and one to two days at 86 degrees. Read more...