how smart are these things?
Another technique for capturing seals is known as wave-hunting: Orcas spy-hop to locate seals resting on ice floes, and then create waves by swimming together in groups to wash over the floe. This causes the seal to be thrown into the water where another Orca waits to kill it. This behaviour has only been recorded a few times and it is not known how often it occurs. The most recent recorded instance in April 2006 ended with the group of Orcas actually returning the seal to the ice floe after they had shown the younger animals how to properly perform the technique.
Orca – Wikipedia, the free encyclopedia