If you are maintaining your own lawn there are many things to watch out for. As the problems mount it is good to know which ones to focus on, like killing ants or letting them run their course. Fighting battles you cannot win or do not need to win only wastes time and money. Manage which problems you attack first to achieve a healthier lawn.
Ants Don't Kill Grass
Ants will not kill grass per se. In other words, their main target is not to eat or devour your lawn. It's quite the opposite. Ants exist to build colonies. They won't even feed on your grass. Other insects do that. There is little about the ants themselves that damages your lawn or prevents it from growing.
The Colony Is Growing
The only time you need to worry about ants harming your lawn is if the colony becomes too large, or there are just too many colonies in your lawn. It's when the actual digging and building of the ant colonies gets out of hand that problems begin. Ants make large dirt piles as they clear out pathways under your lawn. This may damage your root system and, in the very least, makes for an unsightly scene.
To manage ant colonies, use an ant colony killer designed for outdoor use. These are available at hardware stores. The one you need depends on where you live and what types of ants you have. Ask the clerk for advice or try to match the type of ant to the proper ant killer. Specifications on the ant bombs and sprays will show you exactly which products kill certain types of ants.
Bugs to Worry About
Armyworms (which look like maggots) bill bugs (which look like black beetles) and grubs (small round worms) all eat grass. These bugs in large numbers will kill your grass and should be managed with the proper chemical pesticides. Grasshoppers and regular earth worms are two more pests that generally will not kill your grass. Only when these two are in large numbers should you begin to worry.
Fire Ant Queens
It is also important to note that today, after adapting to chemical pesticides, fire ants typically have more than one queen. In the past, these ants had a single queen, which caused the entire colony to die when it died. When managing fire ants with pesticides, several treatments may be required. Fire ants make very large colonies and therefore can destroy your roots and ruin a lawn if not properly managed.