“Seriously, folks, get your shotguns,” said Jonathan Stein in Mother Jones. According to a new study, Santino, a 30-year-old chimpanzee in Sweden’s Furuvik Zoo, creates “stockpiles of weapons”—okay, stones—to throw at zoo visitors, even hacking off throwable discs of his concrete enclosure. What his “weaponizing” shows is that chimps can plan for the future.

To be fair, said Coco Ballantyne in Scientific American, Santino’s rock-throwing started after tourists began laughing at his daily 11 a.m. “macho display” of dominance—the rock missiles would make the crowd disperse. But his premeditated, morning rock gathering has become “increasingly sophisticated,” and does seem to suggest that he can calmly prepare for a future agitated state.

The Santino case is “one of the more elaborate examples of contingency planning in the animal world,” said David Brown in The Washington Post. But some primatologists question its “novelty,” noting that several studies have shown some level of advance planning in chimps. Either way, Santino’s throwing days may be over—the zoo castrated him last fall, to cut his testosterone level.