Do paired hamsters adjust to a shifted light schedule faster than solo hamsters? Every animal has a biological clock (an internal timer that follows day-night cycles). Disrupting that cycle can change behavior. You house six hamsters in four cages. Two cages hold single hamsters and two hold pairs. All follow a 12-hours-on, 12-hours-off light schedule for five days. Then you shift the schedule by one hour for half the cages. You track exercise wheel use over the next five days. Paired hamsters adapted to the new schedule more quickly. Solo hamsters took longer to return to normal activity levels.