Bats Use Magnetic "Compass"

Another interesting bat story:

"Some bats find their way home using an internal 'compass' that senses Earth's magnetic field—similar to those believed to be used by migrating birds—researchers say.
"Princeton University biologist Richard Holland in New Jersey and colleagues found that exposure to artificial magnetic fields confused such bats, causing them to fly in the wrong direction.
"The finding, reported in tomorrow's issue of the journal Nature, is the first of its kind in bats and helps fill in a gap in scientists' understanding of how the animals navigate." ...
"The new study suggests that a magnetic sense may help bats navigate over longer distances, such as when returning to nightly roost sites."
"Holland theorizes that the bats, like some birds, also use sunset as a directional marker. This may let the animals fine-tune their internal compasses and adjust for the difference between magnetic and true north.
"'It is interesting that our bats, which usually fly only a few miles, appear to use the same mechanism as migratory birds that fly thousands of miles,' Holland said." ...
"Scientists know of two kinds of magnetic orientation. In one, a simple compass sense is based on particles of a mineral found in many organisms known as magnetite.
"Some birds can also 'see' changes in light intensity in different locations within Earth's magnetic field.
"This more sophisticated sensory apparatus provides an internal 'map sense' of where the birds are on the globe.
"'We don't know if bats have a light-dependent compass,' Holland said. 'But they do have magnetite in their bodies.'"