What is Lennie acting like when he drinks water from the pool?

When Lennie drinks water from the pool, he behaves like an animal, demonstrating his childlike innocence and lack of awareness of social norms. His actions reflect his simplistic nature and desire for basic needs, as he is more focused on quenching his thirst than considering the implications of drinking from a potentially dirty source. This moment highlights both his vulnerability and the stark contrast between his instincts and the expectations of the world around him.