After all the effort you've put into your yard to make it enjoyable, the only ones who seem to be enjoying it are thousands of tiny freeloaders who have made it an unpleasant place for everyone else. Ants take over areas in large numbers, negating their tiny size by bringing everyone they know to join them. If ants have taken over your lawn, you don't have to stand idly by. Follow several strategies to send ants on their way.
Clean up your yard to remove excess vegetation and make sure that the lid is tightly secured onto the trash can. Cutting off any kind of food source will make your yard unappealing to ants.
Dig a hole into an anthill and drop a piece of dry ice into it. Protect yourself while digging up angry ants by tucking your pants into your boots or shoes and wear long sleeves. Cover the dry ice back up with dirt. This will make living conditions for ants unpleasant--if they survive. If the queen dies off, the ants will move elsewhere.
Pour soapy water all over their anthill. Use a shovel to break up the soil to allow the soapy water to penetrate deeper into their home. The soap will kill them if they don't drown first. This is a good way to kill off large numbers of them quickly. You may need to repeat this several times to make an impression.
Place a piece of fruit or some other type of food bait on top of a mound of dirt. When the ants swarm it, use the garden hose to soak them. This will drown many ants quickly. Repeat this as often as needed to put a noticeable dent in your ant population.
Sprinkle dry grits or cornmeal in areas that you have seen lots of ant activity. The ants will bring the food home and feed it to the others. Ants can't digest either of these things and many will die. If the queen eats it, the others will be forced to move on after she dies.