Effects of Light on the Metabolic Rates of Mice (Mus musculus): Are They Afraid of the Dark?

Addy Evans, Samantha Dutcher, Kourtney Dean, Sarah Gardner


Based on the idea of mice being more active at night because they are nocturnal creatures (Randy 1981), we ran tests to discover if a mouse’s metabolic rate increased in a dark environment compared to a brighter environment. To test this, we measured the metabolic rates of three different mice in light and dark using a respiration chamber, a CO2 sensor, and a fabric covering. We found that a mouse’s metabolic rate actually increased in a bright environment and decreased in a dark environment. Originally, our hypothesis was that a mouse’s metabolic rate would increase in the darkness since they are nocturnal creatures. After our trails, we have now hypothesized that our unexpected results could be because the mice are subjected to more stress from seeing us move and being able to observe the lab as compared to not being able to see anything at all in the dark. 

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