Killer whales are rightly considered amongst the greatest predators in the ocean – and humpbacks the gentle giants. This isn't always the case, though. | National Geographic UK

Bubble-net feeding is a cooperative hunting strategy used by humpback whales to hunt fish, like herring. It is a learned behaviour so each generation of whales must teach their young the strategy. Humpback whales use their powerful vocalisations to scare fish into a group, they then herd the fish before a final group of whales blow bubbles to force the fish into tight balls near the surface. All the whales then lunge for the surface and ingest large amounts of fish at once. Tune in to Secrets of