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.
Most people with nyctalopia are able to see normally in the day but in night time, they become blind as mice. Some individuals have so much trouble with nyctalopia that they wear eyeglasses only at night. Night blindness is absolutely inconvenient and it can be dangerous.