ContraPest is the first U.S. EPA registered contraceptive pest control tool designed to reduce fertility in brown and black rats, developed by the U.S. biotechnology company SenesTech. It is a flavored liquid, designed to be attractive to, and to be consumed by, the target animals in order to reduce the population over time. ContraPest is a contraceptive, not a sterilant, so a continuous supply maintains reduced populations. ContraPest was initially tested in Indonesian rice fields, South Carolina pig farms, the suburbs of Boston and the New York City subway, and caused a reduction in rat populations of roughly 40% over a period of 12 weeks. The product was approved for commercial use by the U.S. Environmental Protection Agency in August 2016.