Crows With Self-Control?

Damn those way-too-smart birds:

The new results, published in the April 2014 issue of the journal Animal Behavior, suggest the birds aren’t just capable of controlling their impulses, they also choose when to give in to temptation. The experiments mimic the classic test where kids and adults are left alone with a marshmallow, and promised a better treat if they refrain from biting in. Like many children and adults, crows and ravens waited.
To test the birds’ patience, researchers began by learning their favorite foods. They offered members of the corvid family — seven crows and five ravens — bits of bread, grapes, sausage or fried pork fat and other treats, and noted each bird’s preferences. In a series of subsequent tests, each bird was offered a food item. After delays ranging from a few seconds to ten minutes, they could exchange it for a treat they liked more (sausage and fried pork fat were high on all the birds’ lists), or return it for a larger helping of the same snack.
In a second arrangement, the birds watched as scientists offered up extra helpings of a snack at fixed intervals. If they waited the experiment out, they received four pieces of the food. But they could grab and go at any point, and if they chose to do so, the experimenter stopped doling out treats.
When waiting to exchange a snack for a tastier treat, birds only chose to be patient for higher-quality foods. A bird holding a piece of bread would wait to trade up to a bit of sausage, but not for a second piece of bread. While waiting for treats to pile up, however, corvids wouldn’t stick around for more if they already held a prized treat.
Early experiments with pigeons, chickens and gray parrots suggested birds couldn’t be patient. More recently, studies have demonstrated corvids’ capacity for self-control, so the researchers weren’t surprised by these results with crows and ravens. But they were impressed that the birds waited up to ten minutes on some tests.

I knew crows were smarter than other birds, but these studies are getting kind of scary.  I'd be afraid to try to poison the damn birds because they might drop some of the poison in my unattended beer.