Platypus (Australian duckbill) have all 5 senses like a human. Their smell is the sharpest. They have Jacobson's organs in their mouth so they can smell their food better. Their brains are relatively large for an animal of their size. Their bill is also highly-sensitive. The skin surface of their bill contains forty thousand electroreceptors, which are sensory cells used to pick up electric fields produced by animals' muscle movements. The platypus and hammerhead shark share a special type of sensory neuron that humans and most other animals don't have. Hammerhead sharks and platypi have electroreceptors that they use to sense the electric fields of animals that they might not be able to see in dark water or buried under mud and sand. They use this to find their prey in water.