Picture trying to survive in rivers and streams in eastern Australia. For many animals, a habitat like this would be impossible. Yet the platypus, a mammal about 50 centimeters long, thrives there, thanks to features that scientists call adaptations: traits that help a living thing survive in its environment.
Consider a soft bill that senses tiny electric signals: this adaptation lets it find prey underwater with its eyes, ears and nose shut. Equally important is webbed front feet, which paddle it through the water. Without these traits, the platypus would struggle to last a single season.
As a carnivore, the platypus is an animal that eats other animals; it depends on insect larvae, shrimp and worms. Its behavior matters as much as its body: it dives to the riverbed and scoops up food, storing it in its cheeks. Behaviors like this are adaptations too, even though you cannot see them in a photograph.
The next generation faces the same challenges. Young platypus depend on their surroundings and on adult care. The platypus is a mammal that lays eggs, and the young drink milk after they hatch.
Perhaps most remarkable of all: male platypuses have a venomous spur on each back leg. Facts like this remind us that every animal's body tells a story about the place it lives.