Grand jury is so named because traditionally it has greater number of jurors than trial jury, called a petit jury (from the French word petit meaning small).
Although mice tend to come out in the night when most of the occupants of the house are asleep or immobile. This allows them to stealthily infiltrate any of your food bags, crumbs etc. During the day time, mice will normally not come out, but if opportunities exist then they surely can.
This feeding pattern is very unhealthy for both mice and humans; the CDC statistics agree. The take home message from this study: eat early and eat whatever you like but skip dinner and never have late night snacks. Â© Gary L. Wenk, Ph.D., author of Your Brain on Food (Oxford, 2010)