studies show that A. robustus was not eating large amounts of plants and fruits as a source of protein, but it was instead being fulfilled by other means such as animal or insect protein. Modern human's larger brain size is often attributed to the theory that it was made possible due to an increase in consumption of meat. The remains of KNM-ER 1808, a specimen of Homo erectus dated to around 1.8 million years ago, has often been used as evidence for the hunter model due to its abnormal bone growths pointing to hypervitaminosis A from consuming excess animal liver. However, Mark Skinner has proposed that consuming bee larvae and pupae could also provide enough vitamin A to cause hypervitaminosis A. Due to insects nutritional value and abundance, they would also be able to provide the necessary amount of protein required for hominin such as H. erectus. Coprolites and cave paintings Before humans had tools to hunt or farm, insects may have represented an important part of their diet. Evidence has been found analyzing coprolites from caves in the US and Mexico. Coprolites in caves in the Ozark Mountains were found to contain insect (ants, beetle larvae, lice), as well as arachnids (ticks, mites). Cave paintings in Altamira, north Spain, which have been dated from about 30,000 to 9,000 BC, depict the collection of edible insects and wild bee nests, suggesting a possibly entomophagous society. Cocoons of wild silkworm (Triuncina religiosae) were found in ruins in Shanxi Province of China, from 2,000 to 2,500 years BC. The cocoons were discovered with large holes in them, suggesting the pupae were eaten. Many ancient entomophagy practices have changed little over time compared with other agricultural practices, leading to the development of modern traditional entomophagy. Insect consumption in human cultures Traditional cultures Many cultures embrace the eating of insects. Edible insects have long been used by ethnic groups in Asia, Africa, Mexico and South America as cheap and sustainable sources of protein. Up to 2,086 species are eaten by 3,071 ethnic groups in 130 countries. The species include 235 butterflies and moths, 344 beetles, 313 ants, bees and wasps, 239 grasshoppers, crickets and cockroaches, 39 termites, and 20 dragonflies, as well as cicadas. Insects are known to be eaten in 80 percent of the world's nations. The leafcutter ant Atta laevigata is traditionally eaten in some regions of Colombia and northeast Brazil. In