Leaf Damage

• Several types of ants cause severe leaf damage to plants. Leaf-cutter ants live in colonies that number into the millions, and harvest leaves not to eat, but to take back to the nest. Worker ants return to the nest with harvested leaves and place the pieces into gardens. Other workers use these leaves to grow the fungus that is used to feed the colony. Other types of ants, such as fire ants, will harvest leaves in a similar manner. Workers return the leaves to the nest, then use them to feed aphids. These aphids in turn produce honeydew which is used to feed the colony. Harvester ants damage a wide range of plants from grasses and landscape trees to bushes.
  
  

Trunk Damage

• Carpenter ants are among the most well-known of ant species for damaging trees. These ants chew through wood to hollow out tunnels and cavities, depositing the sawdust at the entrance to the nest. The ants' activities rarely do severe damage, but can indicate a larger problem within the tree. They often choose soft or diseased wood as it is easier to chew through, so most trees are already suffering before they become home to carpenter ants. Astute gardeners can sometimes save the trees that are suffering from the ant infestation by diagnosing the other problems within the tree, although the ants themselves are rarely the cause of it. In some cases, the presence of ants can warn of a problem that can potentially spread to other trees, allowing the homeowner to contain the problem or remove the tree.
  
  

Root Damage

• Ants can also damage the roots of the plant. Ground-dwelling ants such as the Argentine ant and the pavement ant build their nests on the ground. Ants can decide to place the nests on open, flat grass or at the bottom of trees, but it either case the nests can begin to damage the roots of the plants they come in close contact with. Nests can rob the roots of much-needed water. The ants that live in the nests can also destroy roots when tunneling through the dirt to expand the nest, ultimately resulting in the death of the plant should damage become too extensive. Grasses are particularly vulnerable to this type of damage.
  
  

Repercussions

• Some of the damage can be so severe that it has an impact well beyond the loss of a few leaves or cosmetic damage. In some cases, such as when fire ants infest an area, ants can damage or destroy the reproductive structures of plants and flowers. When this occurs, plants not only lose their ability to reproduce, but also widespread damage can impact the ability of pollinators such as bees to both spread pollen and survive. The extent of this effect is not fully known, but organizations like the University of Minnesota have suggested that large colonies of ants causing widespread damage can also impact other area wildlife such as birds and small mammals.