A repellent is a substance designed to keep unwanted pests, like insects or animals, away from people or specific areas. Commonly used in outdoor activities, such as camping or hiking, repellents help protect against bites from mosquitoes and ticks, which can carry diseases. They come in various forms, including sprays, lotions, and candles, making them easy to apply. There are two main types of repellents: chemical and natural. Chemical repellents often contain ingredients like DEET or Picaridin, which are effective but may cause skin irritation for some people. Natural repellents, made from essential oils like citronella or lemongrass, offer a more eco-friendly option, though they may need to be reapplied more frequently.