Instinctive behavior occurs when an animal has a particular internal state while it is in the presence of a specific external stimulation called a releaser or a sign stimulus.
How many ships did the U-boats sink? During the war the U-boats sank about 2,779 ships for a total of 14.1 million tons GRT. This figure is roughly 70% of all allied shipping losses in all theatres of the war and to all hostile action. The most successful year was 1942 when over 6 million tons of shipping were sunk in the Atlantic.
By 4 June, when the operation ended, 198,000 British and 140,000 French and Belgian troops had been saved, but virtually all of their heavy equipment had been abandoned. Six destroyers had been sunk, along with eight personnel ships and around 200 small craft, from a total of around 860 vessels of all sizes.