The Animal Kingdom
A look at the different species
Mammals
A mammal is classified as a warm-blooded vertebrate animal that is distinguished by the possession of hair or fur, the secretion of milk by females for the nourishment of the young, and (normally) the birth of live young. Mammals are not limited to terrestrial life, they are also found in aquatic ecosystems.
Reptiles
Reptiles are classified as being cold-blooded vertebrates and are distinguished by having dry scaly skin and typically laying soft-shelled eggs on land. While eggs are laid on land reptiles exist both on land and in water.
Birds
Birds are classified as being warm-blooded egg-laying vertebrates that are in the possession of feathers, wings and beaks. Though all birds have wings not all are capable of flight, some have adapted to running on land while others have evolved to be able to swim.
Fish
Fish are distinguished by being limbless cold-blooded vertebrate animals that have gills, fins, and live in water, either salt or fresh water. Most fish can be identified by the hard scales on the outside of their body, but there are fish that lack scales as well.
Arthropods
An Arthropod is an invertebrate that has a rigid outer skeleton, known as a exoskeleton, a segmented body and many jointed appendages. These are commonly seen by people as insects.
Amphibians
Amphibians are cold-blooded vertebrates that are unique in a way that they change from an aquatic gill-breathing larval stage and as they mature go to a terrestrial lung-breathing adult.
Life cycle of a Frog!