Do I need to spray my home with insecticide if someone in my family has head lice?

No, head lice need a regular blood meal to survive and therefore cannot live in cracks or crevices like cockroaches or other household pests. Spraying furniture, carpets and bedding with an insecticide may kill an occasional stray louse, but serves no real purpose other than providing some margin of psychological comfort. Family members who are already being treated with an effective preventative like Lice Off™ would be exposed unnecessarily to pesticides.