Metacognition refers to humans’ ability to think about their own thoughts and cognition. We make judgments about what we know and then we use those judgments to control future behavior. There is growing evidence in metacognition in some animals, like monkeys, but not in pigeons. The goal of the study is to see if pigeons too exhibit behavioral evidence of metacognition. To do so, we first trained pigeons on a size discrimination tasks in which they had to choose one of two circles which simultaneously appeared on a computer screen, conditional on the color of the background. As the diameters of the circles were made similar in size, the pigeons found increasingly difficult to discriminate between them. We gave the birds the option to make the task easier by pecking a special button (the “increase key”). The pigeons have been trained before to use the increase key to obtain more information and thereby make the task easier when given a different discrimination task. In the current study, the pigeons again used the “increase key” to make the task easier, especially when the circles were similar in size. Our results suggest that pigeons have some kind of metacognitive knowledge as to the accuracy of their performance and behave to enhance the likelihood of responding successfully.