Animals dominate human conceptions of life on Earth not simply by their size, abundance, and sheer diversity but also by their mobility, a trait that humans share. So integral is movement to the conception of animals that sponges, which lack muscle tissues, were long considered to be plants. Only after their small movements were noticed in 1765 did the animal nature of sponges slowly come to be recognized.<br /><br />Animals - National Geographic Kids<br />Animals from kids.nationalgeographic.com<br />Animals. Animal Types. Mammals. Mammals. See More. Birds. Birds. See More. Reptiles. Reptiles. See More. Amphibians. Amphibians