Gibraltar's Monkeys Use Soil to Mitigate Effects of Junk Food Consumption
Researchers have observed Barbary macaques in Gibraltar engaging in geophagy, the consumption of soil, to alleviate digestive issues caused by eating human snacks. This behavior is particularly prevalent among monkeys that consume food from tourists, such as chocolate and crisps, which are high in sugar and fat. The study, conducted between August 2022 and April 2024, documented 46 instances of soil-eating among the macaques. The researchers suggest that soil, especially clay-rich types, may act as an antacid, helping to neutralize stomach acidity and adsorb toxins. This behavior is thought to be socially learned, with younger monkeys observing and mimicking older ones. 
