Harold Maxwell-Lefroy, the agricultural pioneer who founded Rentokil, was a maverick and a driven man. He was the first to apply the scientific method to dealing with insect pests, which saved innumerable crops in India and the Caribbean, where he worked with farmers. Suddenly the destruction of livelihoods by pests no longer needed to dominate the future. He became Professor of Entomology at Imperial College and developed anti-pest chemical treatments that led to Rentokil (trademark rules barred him from calling it Entokil), which became his most tangible legacy.