Three years ago, I was visiting Banff National Park with my wife's family, and I can attest that those ground squirrels are exactly that cheeky.

If you get the chance, read about the work palaeontologist Charles Dolittle Walcott did in the Burgess Shale at what is now Yoho National Park: Walcott and his team placed explosive charges into select portions of the Shale to loosen rock for fossil collecting, and they backed off for lunch after setting it off to wait for any slides to subside. The ground squirrels realized that explosions meant humans with lunches, and humans with lunches meant suckers willing to feed cheeky ground squirrels. The little rodents became so familiar with the routine that when the team returned two years later to resume digging, the first shot brought out all of the ground squirrels, expecting to be fed.