A male chimpanzee in a Swedish zoo planned hundreds of stone-throwing attacks on zoo visitors, according to researchers.
Keepers at Furuvik Zoo found that the chimp collected and stored stones that he would later use as missiles.
Further, the chimp learned to recognise how and when parts of his concrete enclosure could be pulled apart to fashion further projectiles.
...
Crucial to the current study is the fact that Santino, a chimpanzee at the zoo in the city north of Stockholm, collected the stones in a calm state, prior to the zoo opening in the morning.The launching of the stones occurred hours later - during dominance displays to zoo visitors - with Santino in an "agitated" state.
This suggests that Santino was anticipating a future mental state - an ability that has been difficult to definitively prove in animals, according to Mathias Osvath, a cognitive scientist from Lund University in Sweden and author of the new research.
...
Dr Osvath embarked on the study after zoo staff discovered caches of stones in the section of the enclosure facing the public viewing area.Since the initial discovery in 1997, hundreds of the caches have been removed to protect visitors, to whom the caching and the aggressive displays seem strictly related; in the off season, Santino neither hoards the projectiles nor hurls them.
Link
That said, i totally empathize. I, too, often have the urge to hurl projectiles at the public and find the urge is greatly lessened in the off season, as well.
