There are a variety of reasons why ants might be attracted to your plants. Some species of ants are actually beneficial to plants, while others can cause damage. It really depends on the type of ant and the plant in question.
Some ants protect plants from herbivores by living in symbiotic relationships with them. These ants deter predators and parasites, and also help to fertilize the soil with their waste products. In return, the plant provides the ants with food and shelter. This mutualistic relationship is beneficial to both parties involved.
Other ants, however, can be harmful to plants. Some species feed on plant sap, which can weaken and even kill the plant over time. Others may spread diseases that affect plants or compete with them for resources such as water and sunlight. If you notice any damage to your plants or suspect that they may be infested with pests, it's best to consult a professional for advice on how to proceed.