Adaptation. instincts, and predators
Platypus are really good at learning how to swim and they eat faster than any animal. Platypus can build thier homes really fast they learn to sneek up on thier pray and then bam attack.
Platypus have alot of predators for example, all kinds of mammals eat platypus. Platypus are at the bottom of the food chain. Platypus eat fish, shrimp, and other kinds of animals.