Hi Alicja,
Yes. Cats like to bother us.
There are a few easy ways to deal with this that may not be desirable. First you could restrict him to an area of the house where he can’t come up the stairs to scratch at the door. Secondly, you could place a barrier every night in front of the door but I assume he would just keep scratching the barrier instead of the door. Thirdly, cats are known to dislike tin foil believe it or not. I’ve had many people say that laying down tin foil keeps the cat off the couch and counters. You may be able to do this diligently for a few weeks, then remove it, and he may have learned not to scratch the door anymore. Hopefully one of these simple suggestions will work.
Determining the cause could be difficult. It sounds like he just wants attention. He may also be anxious so using a supplement, aerosol diffuser, or anti-anxiety medication may improve the condition. A really great idea may be to provide a heated bed for him in a location away from the door. He may like it so much, like most cats do, and decide to sleep there and not bother you anymore. I have had many cats where this worked well. The cats I’ve had have always loved heated beds and it’s actually tough to get them out of it at night. For ideas on how to keep your cat entertained, check out my article, “8 Ways to Entertain a Bored Cat.”
Hopefully one of these ideas would work. Good luck!
Dr. Clayton Greenway