Forensic entomology is the study of insects in relation to a deceased person and has proven useful in the field of forensic science, due to the versatility in how these insects are analyzed . The defined life cycle of some insects allows various developmental stages to be used to determine the time of death, whether the body has been moved, and many other elements of a crime (James, Nordby, 2005). Insects can be analyzed based on their life cycle stage, what region they come from, what they ingested while feeding, etc. As helpful as the insects are in investigations, they also have the ability to contaminate crime scenes and cause problems for forensic investigators. The most common insect used to identify time of death in the field of forensic entomology is the puffer fly, because they are most often the first insect to colonize the body (James, Nordby 2005). Midges arrive at a body within ten minutes of smelling it and lay eggs soon after (Shipman 2011). The average life cycle of a blow fly is “16 to 35 days, depending on temperature and environmental conditions” and begins with the larval stage (Texas A&M). The larval stage itself is divided into first, second and third instars (James, Nordby 2005). First instar larvae are weak and lack the mouthparts necessary to break the skin, so the female fly will deposit her eggs near an open wound or natural body orifices, where the larvae can feed on the liquids present (James, Nordby 2005 ). Second instar larvae are stronger, larger and have special proteolytic enzymes that they use to enter the body (James, Nordby 2005). Proteolytic enzymes are “any group of enzymes that break long chain molecules of proteins into pieces of paper……, and Nordby, J.J. (2005). Forensic Science: An Introduction to Scientific and Investigative Techniques. (2nd ed., pp. 138-143, 143-144). Boca Raton, Florida: CRC Press.North Carolina State University. (2013). Blow the flies. Retrieved from http://ipm.ncsu.edu/ag369/notes/blow_flies.html Shipman, M. (2011, 11 01). Digging up clues: Searching for buried blowflies will help crime scene investigators. Retrieved from http://news.ncsu.edu/releases/wmswatsonblowfly/Shipman, M. (Photographer) (2011). Digging up clues: Searching for buried blowflies will help crime scene investigators [Print]. Available from http://news.ncsu.edu/releases/wmswatsonblowfly/ Sparks, D., Oeltgen, P., Kryscio, R., & Hunsaker, J. (1989). Comparison of chemical methods for determining the postmortem interval. Journal of Forensic Sciences, 34(1), 197-206. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/2918279