Natural toxins are harmful substances produced by living organisms, such as plants, animals, and microorganisms. These toxins can serve various purposes, including defense against predators or competition with other species. Examples include ricin, a potent toxin found in castor beans, and botulinum toxin, produced by the bacterium Clostridium botulinum. Many natural toxins can be dangerous to humans and animals if ingested, inhaled, or absorbed through the skin. Some plants, like poison ivy, contain compounds that can cause allergic reactions, while certain animals, such as poison dart frogs, have skin toxins that deter predators. Understanding these toxins is crucial for safety and environmental health.