Article: On Ant Navigation

On Ant Navigation

The following points are made by Francis Ratnieks (Nature 2005 436:465):

1) There are probably 20,000 ant species and they do not all use the same
navigational methods or have equal navigational abilities. Many can reorient
on trails by using external cues, including landmarks and the position of
the Sun. Leafcutter ants are even thought to use the Earth's magnetic field.
But recent research has shown that one common ant, the pharaoh's ant,
Monomorium pharaonis, has a sense of geometry, and other species probably do
as well.

2) A pharaoh's ant colony forms a foraging-trail network leading from the
nest entrance into the surrounding environment. These trails form Y-shaped
branches with an internal angle of approximately 60 degrees as they lead
away from the entrance. Ants walking the wrong way along a trail are unable
to reorient at a trail bifurcation if the angle is 120 degrees. But if the
angle is less, then they can. Angles less than 120 degrees give the "Y"
bifurcation a nest-environment polarity, whereas at 120 degrees there is
only symmetry. The ability to reorient is maximized at the natural
bifurcation angle of 60 degrees.

3) Natural selection has made insect societies good at solving a problem
that is simple to state but hard to solve -- to send foragers to where the
food is. Because social insects have been solving this complex dynamic
problem for millions of years, they have probably evolved some simple and
elegant solutions. We should care about these solutions because human life
depends more and more on engineering systems that must solve similar
problems to function efficiently -- electronic messaging, grid computing,
transmitting electricity and traffic regulation to name a few. One obvious
lesson we might learn is how to make our systems more reliable and robust.
If there is one thing that natural selection should be good at, it is
eliminating solutions that are not robust. The colony or organism that
"crashes" will soon be a dead one.

Full Text at ScienceWeek
http://scienceweek.com/2005/sw051021-6.htm

Posted by
Robert Karl Stonjek


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