Insect repellent is a substance applied to the skin, clothing, or other surfaces to deter insects, particularly mosquitoes, ticks, and flies. These products often contain active ingredients like DEET, picaridin, or natural oils such as citronella and lemongrass. They work by masking scents that attract insects or by making the skin less appealing to them. Using insect repellent is important for preventing bites that can transmit diseases like West Nile virus and Lyme disease. It is available in various forms, including sprays, lotions, and wipes, making it easy to apply during outdoor activities like camping, hiking, or gardening.