Though the squids have excellent eyesight, a keen sense of smell, and the ability to squirt jets of dark ink that mask their escape they can't escape a sperm whale, which hunt them ruthlessly and easily. According to squid-experts of the Marine Biological Laboratory in Woods Hole, Massachusetts, the numbers of squid that are eaten by sperm whales far exceed those harvested by men for food on a worldwide basic. It is a mystery about the whales managing to subdue such able prey.
One of the researches reveals that more than 20 years ago, it is speculated that the whales use powerful ultrasound shrieks to knock their squid prey senseless before scooping them up. Just like bats and dolphins, some whales might use ultrasonic clicks to find prey and navigate. The sperm whales locate their prey visually, by searching for bio-luminescence produced by the movements of their prey or sperm whales create a zone of stimulated bio-luminescence around the mouth, which attracts squids and other visual predators. If sperm whales search for silhouetted prey, they should be oriented upside-down to improve visual coverage and to facilitate the transition from search to prey capture. They capture the prey near the surface. They swim at a steady pace, little rapid acceleration and spend most of their time foraging at depths with the greatest potential for stimulated bio-luminescence.
