News Archaeology Some monkeys accidentally make stone flakes that resemble ancient hominid tools The find suggests some Stone Age cutting tools were products of chance, not planning In Thailand, long-tailed macaque monkeys (shown pounding open oil palm nuts with rocks) inadvertently bash off pieces of stone, raising questions about whether some of the earliest known hominid tools were made on purpose. Lydia V. Luncz Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Bruce Bower March 10, 2023 at 2:00 pm Monkeys in southern Thailand use rocks to pound open oil palm nuts, inadvertently shattering stone pieces off their makeshift nutcrackers.