What is this tapping in/on my bedroom wall?

Could be air in your pipes, especially if you've just started using the heat regularly.

Mice running around would've made taptaptaptaptaptaptap sounds. They usually hide in ceilings when it gets too cold. They nest there and sharpen their teeth and claws on the beams -- you'll know when they do because it really sounds like something clawing at or chewing on wood.

That being said, it probably isn't an animal or insect, if the sounds are taps or taptaps at regular intervals. I agree that it sounds more like creaky heating pipes. Why they creak more these days is probably brought on by the colder weather. Likewise, they shouldn't creak or tap as much when it gets warmer in March.

It could be from heating pipes which can make a lot of noise as they heat up and cool down, but only if it happens only during the heating season.

Why only the bedroom wall? Bug and vermin are usually near food sources

Central heating pipes?

wood eating beetles in your walls will make noises you can hear . but they are more like tick tick as they chew wood than tap tap.

roaches are definitely a possibility. they live inside the walls and you can hear them doing whatever they're doing

Did you try tapping back?

is your last name gacy