Are they fire ants?

Those aren't fire ant mounds/hills. Ants, as a rule, don't need to be eradicated at all....where did you get that idea? Fire ants, argentine ants, crazy ants, and a very few others need to be controlled, but others? I don't think so.

Are they doing any damage to your plants? No. Then there is no reason to eradicate them.

Fire ants are red and easy to ID. They are the only variety that poses a garden problem. If you type 'ants' in the search bar here you'll find many discussions about their role in gardening and why they are generally considered garden-neutral and sometimes beneficial.

If you feel you MUST get rid of them for some reason then just wet the area thoroughly and they will move on - which, if you have had a lot of rain, is probably why they moved into the garden in the first place as they discovered the soil there drains faster.

Dave

Well they are displacing soil, especially near my parsley and cukes. Over time who knows what the consequences could be. I decided to open those mounds up using a stick (including all satellite mounds) poured a reasonable amount of DE in those holes then just mixed the soil/DE mixture up to flatten the ground. Oddly did not find many ants scurrying around.

True but its far less soil displacing then we do weeding and planting. And overtime they also fertilize the soil with beneficial droppings, aerate the soil, improve soil drainage, and prey on soil dwelling pests that do eat plants - like slugs and snails and other "bad guys". In most cases their benefits far outweigh any damage done. That's why so called prophylactic pest control isn't recommended. It usually does more harm than good.

Dave

I agree that if the ants aren't hurting anything, then don't bother trying to get rid of them. If they are fire ants (and I agree those don't look like fire ant hills) such that they are hurting YOU, just get some bait and put it on the mound. If you have fire ants in your garden, you'll pretty quickly have them everywhere, so some bait would be a good investment. That bait works far better than DE does on fire ants. In Texas, if we relied on "organic" control for fire ants, we'd be positively flaming from their fire. Texas fire ants would laugh DE off.

All bugs do not require killing, and ants are better than neutral. See all those dead bugs, flies and caterpillars on the soil surface? No, you don't. They've been carried down into the ground by the ants, to be broken down by rotting and eating, and thus making just a bit more humus (actual, not the bogus commercial fake humus). To kill these things that are helping you out, just dump a shot glass full of DE right on the hill and walk away.

"Over time who knows what the consequences could be."
If you mean BAD consequences: none.

All points well taken. It's just that the thought of harvest time times makes me feel uneasy knowing that an army of ants has been living among my greens. Yeah I'm probably just being pedantic but after a few years of failed crops for various reasons I am trying to be extra vigilant this year. Better safe than sorry. If my garden was much larger I would not be worrying so much since I would have a better chance of successful crop production.

No need to feel uneasy. Ants aren't 'dirty'. They don't carry diseases. Any healthy garden has a myriad creatures living in it and there is no reason to be concerned about most of them. If you really want the ants to move on just disturb their nests either by cultivation or pouring some water into them.

You're uneasy that ants have been living among your greens? Why? Add some protein to those greens!

http://www.slate.com/articles/life/ft/2011/03/ant_eaters.html

Ants "farm" aphids and other insects that produce honeydew. If the ants start climbing up your plants, I'd be on the lookout for undesirables.

DE kills ants indoors, but it is ineffective outdoors. You could try the stick & soapy water instead...

> but after a few years of failed crops for various reasons I am trying to be extra vigilant this year.>

Vigilance is good but at some point we all have to accept that sometimes garden crops fail. It happens for lots of reasons and many of them are beyond our control. That's regardless of the size of the garden or how many years experience one may have. It is the very nature of gardening.

The perfect garden with a perfect harvest is an impossible dream. And focusing on that goal can quickly turn any of us into an obsessive-compulsive gardener inclined to panic and over-react. That not only takes all the fun out of gardening and defeats one of its primary purposes - relaxation and a sense of accomplishment - but it usually leads to actions that create more problems for us and for the garden.

Relax and enjoy your garden. Nature will take its course no matter how much you fight it.

Dave