Animals are heterotrophic. Animals require oxygen for aerobic respiration. Animals reproduce sexually, and in some cases asexually, or both.
Most animals are motile during at least part of their life cycle.
Cephalization means having a definite head end, usually with feeding and sensory features. The segments may be grouped and modified for specialized tasks, as for example in insects. Sponges have an asymmetric body with no true tissues, no organs. Flattened cells cover the exterior. Collar cells line the interior chambers.