The reason Martians don't appear to have any locks is because their society is just that regimentedWith the exception of Dropo, whom everyone treats like a mental deficient, nobody even thinks about stepping out of line by trying to go through doors that aren't theirs. Therefore, why bother with locks?
- Maybe the Martians are related to the Kazons from Star Trek? They're so hard-wired into obedience that you can make an inescapable prison for them by drawing a line on the ground and telling them not to cross it.
Santa actually did try to come to MarsBut the ancient Martians kept shooting down his sleigh