Reptiles and amphibians together are known as herptiles. These animals are grouped together because they are ectothermic, which means that they cannot regulate their body temperature internally, but must use their environments to control temperature. Common temperature-regulating activities include basking in the sun, burrowing or hibernating. The difference between reptiles and amphibians relates to the way they breath. Reptiles generally have only one lung. Amphibians may have lungs, but they also breath through their skin. Both reptiles and amphibians live on land (terrestrial), in the water (aquatic) or both (semi-aquatic).

There is a wide range of animals that fall into the category of reptiles that come from every land area around the world. The most recognized of these are:

Amphibians

• Frogs and Toads
  
• Caecilians
  
• Urodeles
  
  • Salamanders
    
  • Newts

Chelonians

• Turtles
  
• Tortoises
  
• Terrapins

Crocodilians

• Alligators
  
• Caiman
  
• Crocodiles
  
• Gavial
  

Invertebrates

• Arachnids
  
  • Scorpions
    
  • Spiders
    
  • Tarantulas
    
• Insects
  
  • Centipedes
    
  • Millipedes
    
  • Earthworms

Lizards

• Chameleons
  
• Geckos
  
• Iguanas
  
• Lizards
  
  • Agamas
    
  • Anoles
    
  • Monitors
    
  • Skinks

Snakes

• Nonvenomous
  
  • Black Snakes
    
  • Boa Constrictors
    
  • Garter Snakes
    
  • King Snakes
    
  • Milk Snakes
    
  • Pythons
• Venomous
  
  • Rattlesnakes

Not all reptiles are allowed to be kept as pets, particularly those that are dangerous to humans, such as most venomous snakes and crocodilians.