All Pure Titans lose their sense of being sentient; they are incapable of thinking and controlling their movements. Often, they aimlessly wander around and wait when a more powerful Titan Shifter summons them. Despite this, they are subconsciously eager to regain their humanity and return to their original form, where they can have complete control of their bodies. This is mainly the reason why Ymir’s Pure Titan devoured humans, as she was instinctively aware that the only way to return to humans was by consuming one of the Nine Titan Shifters.