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.
You see, although raccoons are primarily nocturnal, they do often get some stuff done during the day. It is not at all unusual for a raccoon to be active in the middle of the day. They can't just sleep from dawn to dusk without doing anything. They may go off in search of food or drink.