Ants

Asked April 25, 2019, 4:15 PM EDT

I have ALOT of ants in my yard. Lots of small mounds covering most areas of my lawn. How do I get rid of these ants? I have oak and maple trees but they seem to hang out more by the maple trees.

Kent County Michigan

1 Response

The approach to management of ants in the lawn depends a lot on the type of ant and whether or not you can tolerate their presence. Most ants will not do significant damage to the turf and if the turf is well cared for in terms of nutrition and watering, the grass will grow in to the point where you won't even know the ants are there within a few weeks. However, some species of ants in Michigan can bite and/or sting aggressively, and you may need to eradicate them from your lawn. Another sometimes undesireable species is carpenter ants (Camponotus spp.). All ants are fundamentally beneficial, especially in natural areas, but if you feel that they are in danger of damaging your home or injuring your family, then you may choose to take measures to control them.

Here are some options for getting rid of ant mounds in your yard:
The fastest approach would be to use an insecticide to kill the ant colony. You would have to use one that is labelled for use against ants (usually these will have deltamethrin, carbaryl, or acephate as the active ingredient). Be sure to follow the label instructions very carefully. If you decide to go this route, use an insecticidal dust formulation, and sprinkling it on the entrance to the mound only. The ants will pick up the dust and carry it into the nest and kill other ants before they die. This dust will kill any insects it comes into contact with, so take care not to put it near flowers or anywhere that it might be picked up by bees or other pollinators. Also take care to keep children and pets away from the treated area. The insecticide label will contain detailed instructions regarding safety to humans and pets.
If the ants are entering your home, another option is to make a homemade ant bait. There is a recipe for a homemade bait in this MSU factsheet (https://pestid.msu.edu/insects-and-arthropods/pavement-ants/). The factsheet is for pavement ants, which may be a different species from the ant that you have in your lawn, but the bait may still work on your ants. If the ants don't seem attracted to the bait you may need to try a different bait (e.g. sugar or grease-based). Place the bait somewhere in your home where you see the ants and where it is not accessible to children, pets, or pollinators. The baits will take longer to kill the colony so be patient. It might seem like it is not working, but it may take 2 -3 weeks to kill the whole colony. This approach is not likely to work on carpenter ants. You will probably need to seek assistance from pest management professionals if you think you are dealing with carpenter ants. The website https://pestid.msu.edu/insects-and-arthropods/ has a great deal of information about most of the ants that are a problem for homeowners in Michigan.