Ants in the garden? They're on your side
Built in pest control
Ants are an acquired taste for most gardeners. Coming from a country where we have ants called bullants which are nearly 3 inches long and will try to intimidate and stare down humans, I can sympathize. There’s another side to ants, though, and it’s worth considering how they can help out in the garden.
Unless they’re unforgivable, garden vandalizing pests like fire ants, the balance works out in favor of having the ants, rather than exterminating them. Most ants are actually very effective predators of garden pests.
It’s recently been discovered that the innocuous little black ants common around the world, a type called Iridomyrmex, are shift workers. One species clocks on, another clocks off, during the day. These are ferocious, go-anywhere predators, and few other insects will approach them. So their round the clock shift work figures out as good insurance against a range of pests. They’re an active deterrent in the garden.
Each species of ant has a few peculiarities which can help gardeners. Some are tree specialists, happily wiping out caterpillars, grubs, and other nuisances which can infest the garden and obliterate new growth. Other ants are such active foragers that their mere presence will deter other insects. They’re best considered as a long term method of pest control.
Some species also regulate the movements of other ants. There’s one species of ant in Australia, Iridomyrmex purpurea, or the “meat ant”. It doesn’t even have a sting, but these guys are so ferocious, and attack in such numbers, that I’ve seen bush trails where they’re on one side of the track and every other species of ant is on the other. Even the big bullants don’t make a habit of tangling with them.
A few species of ant are only too happy to try to attack termite mounds. Those meat ants, in particular, don’t mind puree of termite for their food supply, and where the ants and termites mix, the termites have a hard time making any headway. If you’ve ever wondered why termites need a soldier caste, the main reason is ants.
Ants are also excellent, thorough, cleaners in the garden. Anything which is protein or carbohydrate based is all food to them, and they can keep a garden spotless on the microscopic scale, clearing up things which can attract pests. If you consider how much material gets deposited in the garden in a week, you can see how useful this role is for gardeners.
As general bug-removers, ants can deal with anything unless it’s a heavy duty proposition like a beetle or citrus bug, which is so toxic they can’t handle it. They’ll also eat eggs and larvae of garden pests on a large scale, and will investigate the garden much more thoroughly than any human for infestations of this type.
Some ants, particularly the aggressive stinging species, can make a garden completely uninhabitable for undesirables like nesting rats and mice, because they’ll attack the young.
The negative sides of ants boil down to comparatively minor issues. The aphid keepers, for example, may need some persuasion that their aphid herds have to go. A few informative sprays of the aphids will convince them they’re in the wrong business. Unless there are aphids around, they revert to normal ant work, so no harm done.
They do eat earthworms, but on an opportunistic basis. Unless flooded out, the worms are invulnerable, so install some drainage in the garden beds to keep your earthworms safe. They’ll also attack and deter snails and slugs driven out by flooding if they can, and don’t get much credit for that. Better to have a lot of ants on your side than a lot of smug, secure slugs and snails.
Some ants are seed eaters, but quite harmless to seedlings. If you have self seeding plants, just make sure you harvest before the ants get interested.
The moral of the story is that unless ants are an actual problem, leave them alone. They’re much more of an asset than a liability.