We humans like to think of ourselves as the only creatures advanced enough to cultivate plants. However, about 50 million years ago, a species of ant in the Brazilian rain forest beat us to it. These attine ants, or leafcutters, have highly honed cultivation skills. The leafcutters march up trees and cut out pieces from freshly sprouted leaves. Then they carry them down into their nests beneath the Jungle floor. The leafcutters drop off their harvest in gardening chambers, where tiny gardening ants take over. This team of ants cleans, trims, and crimps the leaf edges, then smears secretions on the leaves. Finally, they neatly line up the prepared leaf chunks in growing chambers and place specks of homegrown fungus on them. This fungus has the ability to break down the leaves into sugars and proteins, which the ants later consume. Without such resourceful agricultural skills, the ants would not be able to digest the leaves they gather.   Two leading ant experts, Ted Schultz and Ulrich Mueller, liken the ants' agricultural skills to those of humans. They suggest that human farmers have much to learn from these tiny creatures, for the ants successfully employ antibiotics to keep diseases from attacking their fungus. Attine ant gardens are persistently invaded by a mold called Escovopsis, so researchers wondered why the mold seldom overran these gardens. Then researchers observed gardening attine ants carrying a type of bacteria on their undersides that secretes antibiotics to fight the mold, This was surprising enough, but considering that the antibiotics have been effectively suppressing the mold for millions of years, it became clear that the antibiotics were continually adapting to overcome resistance developed by the mold.   Schultz and Mueller also note that the fungus benefits as much from the relationship as its caretaker ants do. After all, the fungus is propagated and protected in well-tended gardens, In the wild, the fungus normally exists on a tiny spot of leaf litter before dying out, but with the help of the ants, it thrives―becoming nearly immortal.　Schultz and Mueller beleive that different types of  fungus have　actually　developed　techniques　to　trick　the　ants　into　harvesting　them.   Not all scientists, though, buy into the idea that attine “fungiculture” is comparable to human agriculture. Naomi Pierce, a specialist in ant and plant interaction, argues that attine ants should not be considered farmers in the human sense of the word. Ants, of course, have not consciously developed agriculture. But while projecting human logic into ants may be misleading. The question of how and why the ants do what they do remains an enticing enigma. Mueller is continuing to search for evidence that will provide an answer.   Meanwhile, the leafcutting ants continue to trickle across the forest floor as they have for millions of years, completely oblivious to the curiosity they generate in their human observers.