There are times, especially during night shifts, where the traffic volume/demand is low. During periods with light stimulation, monotony can occur. Combine monotony with the fatigue that most will experience on a night shift and it can lead to less than optimum performance when needed. Due to ongoing research and sharing of fatigue mitigation efforts in the aviation community, there is a greater understanding of fatigue and how it affects ATCOs, as well as countermeasures that can be applied. However, not much emphasis has been placed on monotony and how this can also affect the overall safety of the operation for ATCOs during night shifts.