Ants are often criticized by gardeners, who tend to say that they’re invasive (though not very harmful). But digging deeper, there are many reasons to keep them in the garden. Indeed, they join in on the heavy work of recycling organic waste, in planting seeds and in protecting certain plants.
→ Also read: ladybug, a beneficial insect…
Ants feed on proteins to grow in their larval stage. They find proteins by hunting different insects (spiders, pine processionary caterpillars, etc.) and by eating small dead prey like lizards.
In this way, ants actively help in control certain pests and in limit diseases. Excretions and remains rejected from the anthill enrich the surrounding plots.
Busy and very organized, ants dig galleries and tunnels to form their anthill, turning and aerating the soil as efficiently as earthworms. They thus assist in soil recycling by bringing up rocks and organic matter.
Some ants (carpenters ants) choose to build their nest under the bark of dead trees. They contribute to breaking down dead wood and old tree fungi, which directly feeds the soil.
Myrmecology is the science that studies the fascinating world of ants.
Ants earn their keep in several different ways at once, from hunting pests to burying seeds. Here is what each activity involves and what the garden gains from it.
| Ant activity | How it happens | What the garden gains |
|---|---|---|
| Hunting insects | Ants need protein for their larvae and hunt spiders, pine processionary caterpillars and other insects, also eating small dead prey such as lizards | Certain pests are controlled and diseases limited |
| Digging the nest | Galleries and tunnels are excavated to form the anthill | Soil is turned and aerated as efficiently as by earthworms, with rocks and organic matter brought up |
| Nesting in dead wood | Carpenter ants build under the bark of dead trees | Dead wood and old tree fungi are broken down, feeding the soil directly |
| Carrying seeds (myrmecochory) | Seeds bear a fleshy elaiosome rich in sugar, protein and fat; the colony eats it and drops the seed | Seeds germinate in a new spot, letting plants spread to different places |
| Guarding host plants | Plants and trees supply shelter and extrafloral nectar in exchange | Defoliating insects such as processionary caterpillars are kept off |
| Visiting flowers | Ants are drawn to flower nectar, though they are less effective than bees | A modest share of pollination, which still counts |
Taken together, these habits explain why an anthill in a border is more often an asset than a problem.
To disperse seeds or propagules (organs that ensure the multiplication for certain moss species), many plants use ants for transportation. We call this partnership, myrmecochory.
💡 This ingenious process complements seed dispersion by wind and the plant’s own mechanisms.
How does it work?
Some species that benefit from myrmecochory:
Although ants are attracted to the nectar of flowers, they are less effective than bees. However, their role is important because all pollinators are useful in the garden.
If you want to keep ants away, you must first get rid of aphids in the garden. There are also effective organic ant treatments.
L.D
