No, the ants are not eating your peonies. Nor do they cause any damage whatsoever to the plant or its flowers. If ants are on the flower buds and flowers of peonies, it’s to eat the sweet nectar the buds give off. Run your finger on over a flower bud and taste the sweet nectar that sticks to it: delicious!
And no, the ants “do not open peony flowers by licking them” (another myth I sometimes hear). The flower will open even in the absence of any ants.
Authorities believe that the peony purposely sets out to attract ants. Ants are indomitable predators and offer the peonies they visit protection against harmful insects and other pests, plus they carry away any disease spores they might run into.
So if you see ants on your peonies, it’s simply a sign that all is well. Certainly, no treatment is needed.