A Saltwater Crocodile perfectly posed as it drifts motionless in the current looking for a feed. With superior vision, hearing and smell its no surprise these predators have been around for millions of years. One of their less well-known senses however, 'integumentary sensory organs (ISOs)' make them unstoppable. These small sensory pits cover the crocodile’s body and allow them to detect the smallest vibrations and pressure changes in the water. This means they can sense prey movement with their eyes closed. They also possess counter current scales which means they can drift in the current without producing a ripple. Both these adaptations mean saltwater crocodiles can drift along the banks on an outgoing tide with their mouth open undetected and literally wait for fish and other prey getting swept out of the mangroves to run into them.