Two-footed animals, also known as bipedal animals, have evolved to adapt to their environments due to various factors. For instance, carrying objects, foraging for aquatic foods, avoiding shoreline predators, standing in tall grass for increased vigilance, conserving energy in long-distance walking, etc.  Humans, for example, developed bipedalism for long-distance travel, carrying goods or babies, and improved visibility. With shorter legs, Kangaroo rats use bipedalism to escape predators in their desert habitats.  Birds have evolved feathers that help them fly and keep them warm. They also have lightweight bones that make it easier for them to fly. Some birds have also evolved beaks adapted for different types of food.