How does a platypus use its bill to find food underwater?

The platypus uses a sophisticated electromechanical system to locate food while submerged, as its senses of sight, smell, and hearing are essentially inactive underwater.1

Its bill is covered in soft, sensitive skin that houses both touch receptors and electroreceptors. As the platypus shovels through streambed debris, it uses these receptors to detect the minute electrical signals generated by the muscles of its prey, such as larval insects and freshwater crustaceans. This specialized sensory adaptation allows the platypus to navigate and hunt effectively in its freshwater environment.1