Nicotine pesticide refers to pesticides containing nicotine as the active ingredient. Historically, nicotine has been used as a pesticide due to its insecticidal properties. It works by disrupting the nervous system of insects, leading to paralysis and eventually death. However, due to its high toxicity to humans and other non-target organisms, the use of nicotine as a pesticide has declined over the years. Instead, safer and more effective alternatives have been developed. Nonetheless, nicotine-based pesticides may still be used in some niche applications or regions where regulations permit their use. It's important to handle nicotine pesticides with caution and adhere to safety guidelines to minimize risks to human health and the environment.