SEALS in the open ocean may be able to navigate by the stars.

Whales, sea lions and seals exhibit a behaviour called spyhopping, where they stick their heads out of the water, apparently surveying their surroundings. This led some biologists to suspect that these mammals might use the stars for navigation.

Björn Mauck of the University of Southern Denmark in Odense and colleagues used a specially built pool planetarium to test two harbour seals on their ability to recognise and orient themselves by the stars. The 5-metre round pool was covered by a dome onto which was projected a simulation …