Which group of animals lives on both land and in water?

• A. Amphibians
• B. Reptiles
• C. Mammals
• D. Birds

Answer: (A)

Animals that live in both land and water typically show a life cycle that uses both habitats. Amphibians are the classic example: they usually lay eggs in water, and these eggs hatch into larvae that live in aquatic environments with gills and a tail. Through metamorphosis, they develop legs and lungs and become capable of living on land, even though many still need moist surroundings. This dual use of habitats—water for reproduction and early stages, land for the adult life—is what defines amphibians.

Reptiles, mammals, and birds aren’t inherently tied to both habitats in the same way. Reptiles and birds are largely terrestrial or specialize in particular environments (though some may swim or live near water); mammals include many land dwellers and some aquatic species, but their life cycles don’t depend on an aquatic larval stage like amphibians do.