With a body length of just five centimeters, the Etruscan shrew is considered one of the smallest mammals in the world. However, this size presents certain challenges. The animals must consume food ...

Deep within the dense foliage of Papua New Guinea lives the world’s smallest vertebrate. Meet Paedophryne amauensis, a terrestrial frog so small it’s nearly invisible to the naked eye. Not only do ...

Q. You wrote that blue whales are the largest mammals. What are the largest and smallest animals of other groups? What ecological problems do animals confront by being extremely big or extremely small ...