Will ants actually hurt plants? I would think all that loosening of the soil might be a good thing...

I discovered 2 ant hills right under plants, a fescue grass and a hydrangea. I just kinda dug around and loosened up the dirt and stepped on the hills as best I could. (Quickly, so the ants wouldn't run up my pant legs!)

I do know if you plant seeds near ant hills the ants will carry the seeds off and nothing will come up, learned from experience! Planted a big patch of cosmos seeds last spring and only got 3 or 4 plants, the rest disappeared.

If the colony population becomes large enough they could and since ants are scavangers and their primary job is to clean up our environment they could, and I have often seen them toting seeds, haul away some of your seeds.
On occassion I have had, or seen, an ant colony so large that the plant that colony surrounded died because the roots were exposed to too much air. Most of the time when this happened a good soaking of the soil around that area would cause the wee buggers to relocate, since ants do not like a wet nest.

It is pretty well known that ants farm aphids. So if your ants are agricultural in nature, they will encourage colonies of aphids on plants.

One interesting thing I learned from another forum is that ants help peonies bloom, but eating through the waxy shell on the buds.

M

The ants are not necessary for peonies to blossom but they do like that sweet nectar the blossoms exude just before opening which has led many people to believe the myth that ants are necessary for peonies to blossom.
Ant do "farm" aphids. They collect them and take them back to the nest to feed to those workers in the nest.

Thanks for info, I never thought of aphids. Will have to keep a lookout for them.