What Is an Animal?
What Are the Main Characteristics of Animals?
Animals are living creatures that don't rely on photosynthesis to obtain energy.
Animals need oxygen to breathe (not all plants do).
Animals ingest other animals or plants to generate energy.
Animals have a central nervous system.
Which Animals Are There?
Mammals are vertebrates with hair and almost always four legs.
Birds are vertebrates , that lay eggs and have feathers and a beak.
Amphibians are ectothermic (cold-blooded) vertebrates , that live on land and in the water.
Reptiles are ectothermic (cold-blooded) vertebrates that creep along.
Fish are vertebrates , that lay eggs live in water and breathe with gills.
Insects are invertebrates that have an exoskeleton (chitin).
Arachnids are invertebrates with eight legs.
Invertebrates are mollusks, crustaceans, sponges and worms.