Biological defense mechanisms are strategies that organisms use to protect themselves from harm, such as predators, pathogens, or environmental stressors. These mechanisms can be physical, like the tough shells of tortoises, or chemical, like the toxins produced by poisonous frogs. They help enhance survival and reproduction by deterring threats. In addition to physical and chemical defenses, many organisms employ behavioral strategies. For example, some animals, like deer, may use camouflage to blend into their surroundings, while others, like skunks, may display warning signals before using their defensive sprays. These adaptations are crucial for maintaining ecological balance.