You Place Equal Numbers of Dark and Light Varieties of Feeder

Essay

You place equal numbers of dark and light varieties of feeder crickets into a terrarium containing a species of lizard. After two days, you notice that the dark variety of the crickets was less common than the light variety. What process is taking place on a small scale within the terrarium? Design an experiment in which you would try to determine if color or taste is the primary factor responsible for the selective feeding of the lizards.