Mutagens are substances or factors that can cause changes in the DNA of living organisms. These changes, known as mutations, can occur naturally or be induced by external agents. Common examples of mutagens include certain chemicals, radiation, and even some viruses. When DNA is altered, it can lead to various effects, including cancer or genetic disorders, depending on the nature of the mutation. Understanding mutagens is important for fields like genetics and medicine. Researchers study these agents to develop better treatments for diseases and to improve safety regulations regarding exposure to harmful substances. By learning how mutagens work, scientists can help protect public health and advance our knowledge of evolution.