Answer: The ants are there because something else is feeding on your plant and exuding a sweet substance called honeydew. I'll bet if you closely examined the undersides of the leaves you'd find aphids (or some other insect). Aphids can be controlled with applications of Insecticidal Soap, or you can try hosing them off with plain water. Once the aphids are gone, the honeydew will be gone and the ants will go elsewhere. Best wishes with your garden!
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