Studies on Essential Oils Treatment for Lice: #1: Tea Tree Oil:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3480584/ At 1% concentration, tea tree oil killed 100% of head lice after 30 minutes. #2: Lavender and Tea Tree Oils:https://www.ncbi.nlm.nih.gov/pubmed/20727129 ...