My parents have used
http://www.terro.com...nt-baits-2-pack
Three times so far, once two years ago and two times last year. If you don't mind ant baits. It sounds like you have a lot of Argentine ants, but at least for us, its worked really well on getting rid of a lot of colonies. They tried using it near the pool area and it didn't make a difference though, so you'd probably need a lot if you have a huge problem with them. Just keep in mind they are really messy, so have to be careful handling them or all the liquid comes out and makes a mess. There are other ant baits, but these work by far the best. Should be able to find it at most hardware stores, I think my parents got the baits at Ace Hardware, but Home Depot should have them too.
The other thing to do is make the environment dry for them. But, if you have neighbors that are really close that keep things wet, that doesn't really work too well.
The best thing to do I'd say is a mix of ant baits, making the environment not to their liking (even if neighbors are close) and introduce Monomorium ergatogyna. Some here might not like that last thing, but they do REALLY well at driving out Argentine ants and I've seen in some areas native ants returning when they are around. Monomorium ergatogyna are tiny, but pretty common up in mountains (can be found at really low altitudes too, but more common in the mountains). They are pretty easy to get, as their nests are shallow. They are native, make large colonies and win 99% of their fights against Argentine ants. It would take 2-3 years for them to get to a huge size, so its a long term kind of approach. What you'd do is if you decide to get them, is "bury" them underground by putting dirt over them so the Argentine ants can't kill them right away. Usually I make a hollow hole, put the ants in, and put a flat object in to "block" part of the hole and then cover it with dirt. The flat object is so they don't actually get buried, and keeps a hollow space for them. Then they dig out, and at that point the Argentine ants can't get into their nest or reach them. They may not solve the Argentine ant problem, but they'd help a lot. Some people have said they have driven out Argentine ants in their backyard, so it may depend how bad of an Argentine ant infestation there is. In some areas inside the complex I live in, Monomorium ergatogyna have driven out the Argentine ants, but along the river area they greatly lessen their number so it still helps. With using the liquid ant baits before hand, it could work well. Just of course be sure not to have the ant baits still around if you decide to get the Monomorium ergatogyna.
Also as a final note on the Monomorium. Monomorium ergatogyna hibernate in the Winter, so if you get them, don't expect them to be around late in the year, until early Spring. But, I think they are the best native ant (as far as I know) at actually getting rid of invasive Argentine ants. They actually do pretty well against Solenopsis invicta as well, for areas that have those.
A large infestation is never easy to deal with though for Argentine ants, especially if the outer areas are heavily infested too. That makes it less likely for other native ants to move in on their own. So, it may take a lot of attempts to lessen their number or keep them out of your backyard and then getting native ants instead, but it can be done with persistence.
Just be sure not to spray poison, because unlike pest control, spraying poison actually makes the queens (at least for Argentine ants) go into over production mode and make MORE ants. That is pest control's secret, because otherwise if they got rid of the ants, they couldn't come back again and lose money 
Edited by Vendayn, May 16 2017 - 10:58 AM.
