Question
What is the cheapest way to control ants on your lawn

Answer
Hi Larry.
Chopped lemon and orange peels strewn around.
I read a couple of days ago that sprinkling cinnamon where they are will chase them away.
I have not tried that.
Best to make a healthy enviornment for the lawn critters like toads, lizards and grass snakes, and let them multiply until you have a good sized herd.
I call mine my, "Lawn Livestock".LOL
I figure I am running a few hundred head of the critters now, especially lizards.
I see them running up and down the tree trunks, and along the fence, and I have NO aphids on my roses, not ants, grubs, slugs, army worms, or any of the other harmful insects that like to live in North Texas.
Every spring, when it is time for termites to swarm, I scatter cedar bark mulch all over my yard. Not heavy, just a light covering, and a trail of it about 3 or 4 inches wide and an inch or two deep, all around the foundtion of the house and outbuildings. We have not had termites for the 42 years we have lived in this house, but my neighbord that do not follow an organic program do.
I have always used the cedar bark, knowing that cedar repels a ton of insects.
I have used it to kep ermites away, and to keep the flea and tick problem away. I have dogs.
I have only been on a total organic program for lawn care for about 10 years.
I wish it hadn't taken me so long to get smart.
My back and knees would be in much netter shape, and I would have had as nice a lawn as I have now, instead of a mediocre one.
Sometimes, if I wamnt to coer the whole yard ( like when the fire ants were a problem) I would get cartons of Epsom Salts from Walmart. They have a package that is about a half gallon, and I would get enough to strew all over the yard, and put orange peels through my blender or foor processor, add them to the Epsom salts, mix and cover tightly, let stand overnight. That allows the orange oil to penetrate every grain of the epsom salts, then scatter it all over.
for your ant problem, get enough to strew all over that yard, get oranges and lemons, and put the peels of about 2 large or 3 smaller oranges, and a couple of lemons, to 1 gallon of epsom salts. Put them in a glass continer, as soft plastic will absorb the oil and it will etch it, and permantely ruin it.
I use a gallon pickle jar.
For all my yard, about 4000 sq.ft, I use about 3 gallons.
The mixture of the orange and lemon peels should get rid of all the kinds of ants you have.
Ot put one ounce orange oil, and 1/2 ounce lemon oil and 2 Tablespoons agricultural soap, in 1 gallon of water and spray it all over.
The orange and lemon oil is rather expensive. It would probably be cheaper to use fresh peels and epsom salts.
You can eat the fruit and use the peels.
Charlotte