The animal with the largest brain relative to its body size is the ant. Particularly, certain species of ants have brain sizes that, when compared to their overall body size, surpass those of other animals. Ants are known for their remarkable social structures and cognitive abilities, which include problem-solving and communication skills. The complexity of their colonies and behaviors requires advanced brain functions. While the human brain is larger in absolute size, the relative brain size of certain ant species highlights the diversity of neural adaptations in the animal kingdom.