Forensic entomologists use their knowledge of insect biology and ecology to help determine important details for criminal investigations. They identify insect evidence collected from crime scenes, estimate time of death based on insect life cycles and development rates, and testify in court. Key insect orders that are studied include flies and beetles. By understanding what species are present, their life stages, and accounting for temperature and other environmental factors, a timeframe can be estimated for when insect activity began on a corpse.