Would this experiment require a control group?

hi im doing an experiment- whether a species of beetles are attracted to a specific color...the experimental group would be exposed to different colors at different times. would this experiment require a control group...if so what would it be? Thankyou!|||You would use what is called a crossover study. The subjects function as their own controls. You show the specific color to the beetle and measure its motion toward the color, and then you show the control color to the same beetle and measure its motion toward the color. Then you show another control color, then the specific color, and so on.





By randomizing the order of the control or "treatment" color, you reduce order effects. Maybe after beetle see their favorite color, they get excited and go toward any color for five minutes. By making their favorite color sometimes come first and sometimes come last, you reduce this order effect (if an order effect exists).