Plants provide the pharmacy for animal life. Many animals self-medicate with herbal remedies.
Woolly bear caterpillars carefully select and consume pomegranate leaves rich in an alkaloid that kills parasitic fly larvae laid inside their abdomen.
Fruit flies face a similar problem. Parasitic wasps are prone to lay eggs into fruit fly larvae, a fatal fate for a fledgling fruit fly. But fruit fly larvae know when they are infected. The larvae seek out high alcohol-content fruit, imbibing the boozy fruit to kill the parasites.
Fruit fly moms look out for their little ones by preemptively laying eggs into alcohol-laden food if a parasitic wasp is spotted in the neighborhood. This precaution protects the larvae when they hatch.
Primates know numerous medicinal remedies. Capuchin monkeys eat pepper plant leaves as an antiseptic. They also know that nutmeg fruit has antimicrobial properties.
Chimpanzees treat intestinal worms by ingesting the leaves of plants with anti-parasitic compounds, such as wild sunflower.
Plants have ever been the foundation of human medicine. Before laboratory synthesis developed in the late 1800s, 80% of the substances used to cure diseases were plant derived. Plants still account for ~40% of the drugs taken.
Directly or indirectly, all animals depend upon plants for their survival. Plants are the builders of ecosystems which most land animals inhabit. The more abundant and diverse plant life is in an ecosystem, the more vibrant the living environment is for all that live there. Conversely, a paucity of plant life offers only the meanest existence to animals.