What is the best organic way to get rid of black ants that's taking over my back yard?

The best way that I found to get rid of large colonies of ants is to use powdered yeast, mixed with powdered sugar. It's harmless to the environment and kills off a whole colony of ants rather quicly.

The yeast is eaten by the ants with the sugar, and expands, which kills the ants, and they share it with members of the colony.

It's non-poisonous to animals and plants, and biodegradable.

Ants do serve a useful purpose, in aerating the soil and fertilizing it, though. They can be pests when they get into your house.

Also, ants are repelled by cucumber peel---they won't go near them. If you find a point where ants are entering your home, put a few pieces of cucumber peel there regularly. Again, it's harmless to pets and children, much safer than poisonous sprays.

Mix these ingredients together in a small bowl: 3 1/2 ounces of Jam 1 1/2 tablespoons of wet canned cat food 1 tablespoon of boric acid Place a small amount by the mound. This concoction is a treat for ants and the workers will bring the treat to their queen. The queen gets excited and quickly gobbles up the goody. Within a few hours she will die from heartburn. without her, the colony will die. Make sure the kids and animals steer clear of it. It doesn't take a lot to do the job. I've used this for red ants, may work on black ants as well. Sprinkle a good amount of instant grits around the mound. They will eat this, bloat up and die.

Place a piece of fruit or food onto a pile of dirt. If you don't care to have a mound of dirt just lying around you can put it into a large empty flower pot.

Wait until you see many ants swarming the bait and dump a bucket of soapy water onto them.

Stir the water around in the soil to kill many ants at once. Be sure not to do this near your home, set the planter or dirt pile at the far edge of your property. Repeat this as often as you would like to kill of large number of fire ants

Drown out ants by pouring boiling water over the mounds and into the cracks where they dwell. Roughly 3 gallons of water per mound ought to do the trick

Go to Home Depot and buy an ant bait that is formulated for exterior ants. These baits are organic in nature and safe to use around a lawn or residential yard.

Spray or pour white vinegar on and in the ant hill and all around where you've seen ants. Ants dislike vinegar and will move to new digs.

we have used cornmeal

it will work to kill the nest but the queen has to eat the meal

what ever ant eats the meal they will die

we have tried this and it did cut down on the ants but haven't gotten rid of them all yet we keep trying

we put it down last year and this year --it might not be the fastest but it is very safe for kids and pets

Clearly the solution is an Anteater!

http://en.wikipedia.org/wiki/Anteater

Ha, ha! Try pouring hot water over them several times. It's effective against fire ants so I think black ants will be an easy target.

Not actually organic cure, but I have had good luck using Andro. Almost any outdoor ant killer would should be good, and shouldn't harm your lawn. They are usually available at most hardware superstores (e.g. Lowe's, Home Depot).

Pour kerosene in the middle of the mound and set it on fire. Your grass will grow back even greener.