Static white dots when making nightsky timelapses

When i make nightsky timelapses with my Canon EOS 550D there are static white dots which look like stars, but don't move like the stars. I remember that i've read anything about it long time before, but now it seems to become more.
Can anybody tell me what it is and how to avoid it?

The chip has broken dots. I think it can't repair except stamp it away with photoshop.

Stuck pixels,which could be "repaired" from the camera itself.Don't have a link handy but do a search on how to do get rid of stuck pixels using the "clean sensor manually" option.
Haven't done it in years so dont remember the details, i think you just leave it like that for a minute or so and after reboot camera has gotten rid of some of the stuck pixels.

Here are the instructions:

Take a shot with lens cap on at 1/5 sec and 1600 ISO with auto-focus off.
Go to Sensor Cleaning and turn it on manually but leave lens cap on.
Once it's finished cleaning, switch camera off.
Switch camera on and your dead pixels should be gone.

I was very sceptical of this method, but I tried it on my Canon which also had 2 stuck pixels, and now they are gone.

Thanks Daniel, will try this out and hope it works.
I use my Canon very rare in between, but for night timelapses there's no other choice.

Probably just hot pixels because of noise. I had the same thing with my mark II when I would turn up the iso above 1600 and use it for a few minutes at a time. The sensor would heat up and I would get a really hot red pixel in the same spot.

That is very common with long nighttime exposures. Usually I end up using the spot removal tool to get rid of them. Even my 5d iii usually has a ton of them. Try remapping the pixels. It usually helps at least some.

Yes, what danielschweinert said,although i would take a longer exposure to be sure something closer to 30 seconds.

In between i've made 2 tests with Daniels instructions, but unfortunately it doesn't help and the white pixels are still visible in the nightshots. The 2nd test with only iso100-200.
Spot removal is senseless because i've to this at hundreds of photos by night-timelapses with different darkness. Now i've send a mail to Canon customer support. Will see what they say.

If they can't fix the problem, then money back...