Even if Ratchet did go to sleep, Starscream at most would just do something highly annoying. Just out of spite.

With Ratchet laying down, Starscream glances over his shoulder at him. The room is too quiet and this makes the seeker bored. And a bored Starscream is never a good thing. He's not allowed to touch Ratchet's stuff without being yelled at so he might as well do the next best thing and just bother him.

"What are you reading?" Starscream asks while wandering back over and invading Ratchet's personal space to try and see what's on the datapad.