The independent variable is the variable that is being changed in an experiment. It is also called the manipulated variable. In this case, it would be the amount of sunlight. The dependent variable would be the variable that is being studied. In this case it would be the length of sleep of the mice. The constants would be the variable that are supposed to have an effect on the dependent variable however it is held constant so as to clearly see the effect of the independent variable.
Sorry i don't understand your question. I am really confused.
I believe it can be by eating them
