Natural Selection and Adaptation
You'll be acting like a bird eating bugs. You "eat" a bug by clicking on it but will have only a few seconds to do so. Each background represents a different challenge. Figure out how the background affects the future generations.
The ability of a creature to blend into a background is known as cryptic coloration. For example, the snowshoe hare has adapted to be white during the snowy winter months and not during the rest of the year.