Consider the following scenario: You want to buy a house with a big kitchen and a big yard, but there are only two homes on the market–one with a big kitchen and a small yard and the other with a small kitchen and a big yard. Studies show you’d be about 50% likely to choose either house–and either one would be a rational choice. But now, a new home comes on the market, this one with a large kitchen and no yard. This time, studies show, you’ll make an irrational decision: Even though nothing has changed with the first two houses, you’ll now favor the house with the big kitchen and small yard over the one with the small kitchen and big yard. Overall, scientists have found, people and other animals will often change their original preferences when presented with a third choice.

Not so with ants.

Click on link for the rest of the fascinating experiment.