How do biotoxins protect plants and animals from predators?

Biotoxins, which include phytotoxins (produced by plants) and zootoxins (produced by animals), serve as vital defensive mechanisms against predators and competitors.12

Plant Defenses

Plants utilize chemical defenses to deter herbivory, particularly from insects. These defenses include:32
* Chemical Toxicity: Many plants produce substances like alkaloids, glycosides, or resins that are poisonous when ingested, causing illness or death in predators.42
* Contact Irritants: Some plants possess toxins that cause severe skin irritation, blistering, or pain upon contact, such as the stinging hairs found on certain nettles.4
* Structural and Chemical Synergy: Plants often combine chemical defenses with physical structures like thorns or spines to discourage consumption. Developing tissues, which are nutrient-rich and vulnerable, frequently receive higher allocations of these defensive compounds.3

Animal Defenses

Animals employ venom and other secretions to protect themselves:
* Active Defense: Many animals use venom, delivered via fangs, stings, or spines, to paralyze or injure predators.52
* Chemical Repellents: Some species release odorous sprays or volatile compounds that act as effective repellents. These strong odors often serve as a warning, facilitating learning in predators and enhancing the protective effect of the poison.6