In a research animal facility, mice are typically housed in a rectangular cage covered with a lid. This device is a means of non-invasively and automatically measuring when a mouse (and possibly rat as well) interacts with the lid of its cage. The lid is usually a stainless steel wire grid with space to hold food and water. Mice interact with this lid when they get food and water, and can also spend a considerable amount of time hanging from the cage lid. This device enables the long-term, non-invasive, and automated measurement of eating and hanging behaviour to facilitate the study of sensory disorders (including persistent pain), motor disorders (such as Huntingtons’s disease and ALS), and cancer and chemotherapy; but also other mouse models of disease with proven or suspected alterations in activity or eating behaviour such as cognitive disorders (including Alzheimer’s disease, depression, and anxiety), obesity and diabetes, and “sickness behaviour” that is induced by exposure to infectious agents. This device may also be useful for the large-scale screening of drugs with effects on activity or food intake.