Why does my laptop creak when I breath?

Whenever I have my laptop on my stomach and I breath it creaks. I have a Lenovo Thinkpad and I was wondering if anyone knew how I would be able to stop it as the sound is quite irritating. Sweet as

It is because your stomach is moving the laptop, which cause the screen half to movie back and forth, just a little with each breath and the hinges creak.

If you put your laptop on a table and open it up (like you are going to use it,), grab the top of the screen and move it back and forth just a little and you will hear that same creaking sound.