To be precise, those ants are not eating your plants; they are taking those pieces of leaf back to their nests to feed a fungus that they cultivate in underground gardens. These are fungus farming ants.  The ants bring the leaf fragments to their nest. The ants cannot digest the leaves, but the fungus can. So, the ants chew the leaves, place them on the growing fungus which then digests the leaves to release the stored nutrients. The ants now eat the fungus and get the nutrients. The ants and fungus have a symbiotic relationship wherein the fungus and the ants rely on each other for food.  In the absence of the ants, the fungus will die; in the absence of the fungus, the ants will die.  https://nhmu.utah.edu/articles/fungus-farming-ants

For homeowners, there is not much information available on fungus farming ants in residential landscapes. One species of ant known to harvest leaves in Texas is the Texas leaf-cutting ant, Atta texana. https://citybugs.tamu.edu/factsheets/landscape/ants/ent-1002/

Texas leafcutter ants can cause extensive damage to vegetation, and large colonies of these ants can invade houses and even cause structural damage as a result of their tunneling.  For these ants, chemical control is recommended but can be challenging because they have no known natural enemies and cultural controls are ineffective.  If you suspect that you have Texas leafcutter ants, contact your local extension office at https://extensionentomology.tamu.edu/ for information about how to manage these ants on your property.

It is possible that these are not Texas leafcutter ants; there are other species of fungus farming ants that can cause this type of plant damage. Specimens of the ants shown here were sent for identification to the entomology lab at Mississippi State University, where they were identified as Trachymyrmex septentrionalis, a fungus farming ant common to eastern and southern parts of North America. Although these ants can defoliate plants, they are not known to cause extensive damage and do not

form the huge colonies characteristic of the Atta texana. According to the entomology report, these ants are not serious pests, won’t sting or enter homes, and pesticides are probably unnecessary. If it looks as if these ants are doing extensive damage to trees or shrubs then local extension personnel may be able to offer suggestions for control.

For more on Trachymyrmex ants, see: https://mississippientomologicalmuseum.org.msstate.edu/Researchtaxapages/Formicidaepages/genericpages/Trachy.septent.htm

https://www.srs.fs.usda.gov/pubs/ja/uncaptured/ja_moser029.pdf