swallowing the large seeds of the fruit they regularly ingest. Although they are consumed along with the rest of the fruit, it must be noted that these seeds have no nutritional value for the monkeys. Since tamarins are routinely infected by trematodes, cestodes, nematodes, and acanthocephalans, there is speculation that the deliberate swallowing of these large seeds can help dislodge the parasites from the monkey's body. Bears Similar to the wild chimpanzees, Alaskan brown bears will swallow whole Carex leaves in the springtime to ensure the complete expulsion of parasites during their hibernation. Specifically, as tapeworms thrive off previously digested nutrients in the gut, the rough Carex leaves will lacerate their scolices, facilitating the defecation process. The proactive swallowing of these leaves will ensure low levels of active parasites within a hibernating bear. Ingestion Many examples of zoopharmacognosy involve an animal ingesting a substance with (potential) medicinal properties. Birds Many parrot species in the Americas, Africa, and Papua New Guinea consume kaolin or clay, which both releases minerals and absorbs toxic compounds from the gut. Great bustards eat blister beetles of the genus Meloe maybe to decrease parasite load in the digestive system; cantharidin, the toxic compound in blister beetles, can kill a great bustard if too many beetles are ingested. Great bustards may eat toxic blister beetles of the genus Meloe to increase the sexual arousal of males. Some plants selected in the mating season showed in-vitro activity against laboratory models of parasites and pathogens. Invertebrates Woolly bear caterpillars (Grammia incorrupta) are sometimes lethally endoparasitised by tachinid flies. The caterpillars ingest plant toxins called pyrrolizidine alkaloids, which improve survival by conferring resistance against the flies. Crucially, parasitised caterpillars are more likely than non-parasitised caterpillars to specifically ingest large amounts of pyrrolizidine alkaloids, and excessive ingestion of these toxins reduces the survival of non-parasitised caterpillars. These three findings are all consistent with the adaptive plasticity theory. The tobacco hornworm ingests nicotine which reduces colony growth and toxicity of Bacillus thuringiensis, leading to increased survival of the hornworm. Ants Ants infected with Beauveria bassiana, a fungus, selectively consume harmful substances (reactive oxygen species, ROS) upon exposure to a fungal pathogen, yet avoid these in the absence of infection. Mammals Great apes often consume plants that have no nutritional values but which have beneficial effects on gut acidity or combat intestinal parasitic infection. Chimpanzees sometimes select bitter leaves for chewing. Parasite infection