Have the infested person put on clean clothing after treatment. If a few live lice are still found 8-12 hours after treatment, but are moving more slowly than before, do not retreat. Comb dead and remaining live lice out of the hair. The medicine may take longer to kill lice. If, after 8-12 hours of treatment, no dead lice are found and lice seem as active as before, the medicine may not be working.
Many flea combs made for cats and dogs are also effective.
After treatment, check hair and comb with a nit comb to remove nits and lice every 2-3 days. Continue to check for 2-3 weeks until you are sure all lice and nits are gone. If using OTC pediculicides, retreat in 7-10 days. If using malathion, retreat in 7-10 days only if crawling bugs are found. You do not need to spend a lot of time or money on house cleaning activities.