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.
Ferret natural instincts in the wild spend most of their time in dens underground to avoid predation. Ferrets spend 15 to 18 hours a day sleeping depending on their age. Baby kits and older ferrets sleep more. They are naturally crepuscular, meaning they are most active during dusk and dawn.