animal summary

Learn about the characteristics of animals

Written and fact-checked by The Editors of Encyclopaedia Britannica

Below is the article summary. For the full article, see animal.

Gray whale (Eschrichtius robustus) breaching. — Gray whale (*Eschrichtius robustus*) breaching.

animal, Any member of the kingdom Animalia (see taxonomy), a group of many-celled organisms that differ from members of the two other many-celled kingdoms, the plants and the fungi (see fungus), in several ways. Animals have developed muscles, making them capable of spontaneous movement (see locomotion), more elaborate sensory and nervous systems, and greater levels of general complexity. Unlike plants, animals cannot manufacture their own food and thus are adapted for securing and digesting food. In animals the cell wall is either absent or composed of material different from that of the plant cell wall. Animals account for about three-quarters of living species. Some one-celled organisms display both plant and animal characteristics. See also algae; arthropod; bacteria; chordate; invertebrate; protist; protozoan; vertebrate.

aardvark Summary

Aardvark, (Orycteropus afer), stocky African mammal found south of the Sahara Desert in savanna and semiarid areas. The name aardvark—Afrikaans for “earth pig”—refers to its piglike face and burrowing habits. The aardvark weighs up to 65 kg (145 pounds) and measures up to 2.2 metres (7.2 feet)

In the walrus (Odobenus rosmarus), both males and females have tusks.

pinniped Summary

Pinniped, (suborder Pinnipedia), any of a group of 34 species of aquatic fin-footed mammals comprising seals, sea lions, and the walrus. Pinnipeds live only in rich marine environments and a few inland or tropical freshwater systems. Shaped like torpedoes, pinnipeds have wide torsos and narrower

Common, or northern, pintail (Anas acuta).

duck Summary

Duck, any of various species of relatively small, short-necked, large-billed waterfowl. In true ducks—i.e., those classified in the subfamily Anatinae in the waterfowl family Anatidae—the legs are placed rearward, as in swans, rather than forward, as in geese. The result is a distinctive waddling

fluke Summary

Fluke, any member of the invertebrate class Trematoda (phylum Platyhelminthes), a group of parasitic flatworms that probably evolved from free-living forms millions of years ago. There are more than 10,000 species of flukes. They occur worldwide and range in size from about 5 millimetres (0.2 inch)