Wild blacktip sharks can hear sounds from nearly 250 feet away and pinpoint where they come from; Florida experiments reveal how the predators locate sound underwater

• The study also points to the importance of behavioural experiments in the natural environment.
• Sound does not behave the same way inside tanks, and the reflections from walls can create complicated acoustic patterns that can make an animal’s response difficult to interpret.
• The ocean can hide an entire world beyond the reach of sight.