Title: Why Is My Cat So Active At Night? - Catster
Headings: 
Why Is My Cat So Active At Night?
Also:
How To Encourage Your Cat To Sleep At Night
Install A Window Perch
Get A Birdfeeder
Adopt A Companion
Increase Your Playtime
Never Give In

Content: It’s also a consequence of the typical housecat’s lack of daytime activity while you’re at work. Fluffy usually spends her entire day napping. When you get home from work, her day begins. You provide food, play and social interaction. By the middle of the night she’s hitting her stride and is at her most rambunctious. Research on cat behavior at night shows that even cats who have developed sleep patterns similar to our own still wake several times during the night. Once she’s awake, Fluffy shifts into play mode, leaping at your every movement in bed, trying to entice you to play with her. How To Encourage Your Cat To Sleep At Night
Simply locking her out of the bedroom at night is not always effective. She may yowl and pound at the door to be let back in. The best solution is to increase her activity level during the day so that she sleeps at night.