Ants and Elephants

Just what makes that little ol' ant
Think he'll move that rubber tree plant
Anyone knows an ant can't
Move a rubber tree plant 

I know it is a long way from the Ozarks, but this story was too good to pass up.  The New York Times reports that an African ant which lives on the sweet sap of a variety of Acacia tree attacks elephants that would otherwise eat the tree, successfully defending their home and way of life.

"The tree, known as the Acacia drepanolobium, is a generous home to ants that live in its bulbous swellings and feed on a sugary solution it produces. In return, the ants serve as guardians, instantly attacking any creature that approaches the tree. In the case of elephants, ants crawl up the inside of their trunks and agitate sensitive nerve endings.
“An elephant’s trunk is a truly remarkable organ, but also appears to be their Achilles’ heel when it comes to squaring off with an angry ant colony,” said Todd M. Palmer, a biologist at the University of Florida and the paper’s co-author."

When fed the same tree without ants, the elephants ate them readily.  They are apparently able to smell the presence of the ants and avoid them.  This protective behavior may be important in the ecosystem, as fire moves more readily through grasslands unprotected by trees.  The whole story including a fascinating video can be seen at Current Biology.