As many cat owners know, there is such a thing as the cat witching hour. It usually happens at night – maybe as you're getting ready to go to sleep or perhaps while asleep – when your cat is raring to play. "There are two things here," says Dr. Miller. "The first is that cats naturally have a different wake pattern. They sleep multiple times throughout the day and night, not only during the night. They can cycle through sleep and wake throughout the 24-hour period, and so they are naturally awake at different times."
Also, many cats recognize daytime hours as idle “quiet” time, when human family members aren’t home. In the evenings, however, the entire brood may be home, energizing your well-rested cat. It doesn't help that cats are fast learners, too. That means that every time you get up in the middle of night and give your cat some attention for his craziness, he'll consider this a reward for his behaviour and continue it.