The bottlenosed dolphin is without doubt the most well known member of the order Cetacea. Its habits have been extensively studied along with its physiology and behavior. Bottlenosed dolphins are extremely social and are seen in groups of twenty to twenty-five individuals. These animals are cooperative among one another, as they will aid wounded individuals to the surface to breathe, or help a birthing mother and her newborn calf to the surface. Bottlenosed dolphins are perhaps the second most intelligent animal on this planet, as they have the second highest ratio of brain weight to body weight (1.17 for the dolphins and 2.1 for humans).