Bats use the Earth's magnetic field to navigate and one species has a huge tongue that is longer than its body, researchers have found.
In two separate studies published in the journal Nature, scientists in the US have revealed unusual characteristics of the winged mammal.
Richard Holland ofPrinceton University, New Jersey, showed the homing devices of big brown bats can be altered by artificially shifting the Earth's magnetic field, indicating that the animals depend on a magnetic compass to travel.
"This finding adds to the impressive array of sensory abilities possessed by this animal for navigation in the dark," Dr Holland and his team said in the Nature study. By rotating the magnetic field by 90 degrees clockwise and anticlockwise in relation to magnetic north and tracking the bats' attempts to fly home, the scientists found they flew in the wrong direction compared to other bats not exposed to the changes, who flew directly home.
In another study Nathan Muchhala of the University of Miami taught a nectar bat to drink from a modified straw to measure its 85mm tongue, which is 1.5 times longer than its body.
The bat, which stows its lengthy tongue in its rib cage, pollinates a plant with tubes of the same length. Mr Muchhala suggests the extreme length of the bat's tongue co-evolved with the long flowers of the plant.
