Though you may think that pesticides are a relatively new invention, they have actually been used for hundreds of years. In fact, humans have used pesticides since 2500 BCE, with the materials and methods being both similar and dissimilar from the ones we use today. The first pesticide used was sulfur, which was dusted on crops in Sumeria around 4,500 years ago. Over the next thousands of years, many different toxic materials were used as pesticides, such as arsenic, mercury, lead, and a chemical found in tobacco. With the shift from religion to science, chemicals started being investigated and their development benefitted greatly from this period. DDT, a pesticide discovered in 1939 by Paul Muller, became incredibly popular due to its efficiency and was the go-to choice for many farmers in the coming years. However, in Rachel Carson’s Silent Spring, she uncovered the adverse effects of DDT, one of those being its harmful effects on biodiversity. This eventually led to the banning of DDT in many countries, but the pesticide is still used in some developing countries. Today, pesticides are commonly used in many countries and in traditional farming, though many are moving away to more natural options.