The leaf cutter ant; They get their name from the way they cut leaves from trees, which they then haul back to their nest. They do not eat the leaves, but instead they use it as compost to grow a particular type of fungus that does not grow anywhere other than in leafcutter ant nests. The ants eat the fungus, and feed it to their young. The fungus is grown in football sized chambers inside the nest. There can be 300 or more of these chambers inside the nest, and all of the earthworks to build them might involve the removal of 18,000kg of earth during the lifetime of the nest.
I remember tending to our garden that was opposite our home and next to the rail line and having to deal with Bachacs. They literally had 'tracks' in the grass and were so industrious working all day. The ones with the really big heads had cutters that would remain connected to the partially cut leaves even when their head was detached from the body. They never bothered with anyone unlike the regular ants and the notorious red ants (very small but the sting/bite hurt like hell). The other ant that was similar in built but black in color was called tac tac and we knew to stay away from these guys. The Bachac could really put some hurt on the young tomato plants but we never really bothered about them.
Source:
http://www.amazing-trinidad-vacations.com/leaf-cutter-ant.html
http://www.wiwords.com/word/bachac
