The unrestricted exploitation of wildlife has led to the disappearance of many animal species at an alarming rate, destroying Earth's biological diversity and upsetting the ecological balance. The problem is particularly acute in developing countries. Scientists estimate that various animal and plant species may be disappearing at the rate of one every day, with thousands more on the verge of extinction. Widely sought for everything from medical research, medicinal supplies, and display in zoos, to satisfying the demands of high fashion, the illegal trade in wildlife is a lucrative business, making it difficult to control. The United Nations Environment Programme (UNEP) is actively involved in working with governments, scientists, private organizations and other concerned groups to preserve and protect our endangered species.