Friends or pests
There are enormous numbers of ants in the world, in a multitude of species (over 8,000) with varying characteristics. Members of the Formicidae family, they are related to bees and wasps (Hymenoptera order). They live in highly organized colonies, in vastly differing conditions. The proper place for ants is outside, where they can create their nests underground or in other selected safe sites to store food and provide a space for the queen ants to breed in. A queen ant is technically called a gyne.
Ants as helpers
- ants keep the environment clean by decomposing organic waste, insects and dead animals
- many ants collect and use leaf litter
- carpenter ants accelerate decomposition of dead and diseased timber
- ants improve soil drainage and chemistry: by turning and aerating the soil, they allow water and oxygen to reach plant roots; they also bring pebbles and other particles up to the top of the soil
- ants improve soil chemistry by bringing in their stores of food, enriching the soil with food and excreta; especially increasing nitrogen and phosphorus, they leave behind soil which is more or less pH neutral
- many ants disperse seeds across locations where they can flourish: they preserve the seeds by transporting them into safer nutrient rich habitats where they are protected from seed eaters, drought and fire; caches of seeds can be collected by humans when needed
- some plants are protected by ants from harmful insects, because they produce a particular nectar which the ants eat
- ants prey on pest insects and eggs – including other ants, ticks, termites, scorpions and stink bugs
- weaver ants are used as biological control in citrus cultivation, especially in China
- fire ants control pests on cultivated fields
- red wood ants help control bark beetles and caterpillars
- the large army ants prey on insects, small reptiles, birds and small mammals
- ants and ant plants: plants with with cavities (technically known as domatia if they have formed naturally) can serve as food stores or nesting places for the ants; the plants may get a supply of mineral nutrients and nitrgoen from their tenants' waste; the ants may protect the host plant from predators, whether mammals, other insects or even invasive plants such as vines
- some tropical and subtropical species of ant are totally dependent on their host plants, which in turn depend on their ant colonis to thrive
- rarely, ants are pollinators, for instance of certain orchids
- in some parts of the world certain types of ants are eaten by humans
- large ants such as army ants are used in some countries as sutures after operations
NOTE: to allow ants to do their work on and in the soil, heavy diggers should not be used to clear land for cultivation, as their weight compacts the earth into a hard mass to a significant depth. Plastic sheeting to suppress weeds also prevents ants from working in the soil.
Ants as pests
- some ants can sting, causing a variety of reactions from mild irritation ro serious allergy, according to the type of ant
- some ants protect aphids and mealybugs in order to ensure their source of high-energy honeydew: the protected mealybugs can cause problems for fruit cultivation, especially pineapples
- ants can cause damage if they choose to nest in a building or one’s home
Natural predators
- woodpeckers and other insect-eating birds
- certain types of frog
- flies
- certain fungi
- some caterpillars
- anteaters, aardvarks, pangolins echidnas, numbats
- brown bears, which especially eat carpenter ant larvae and pupae
Natural deterrents against ants
Note: the suggestions given here are based on the wide variety of personal experiences, including our own, which people have shared over the years. Always make sure that you do not use any substances, whether natural or chemical, in any way which can cause incidental harm to yourself, others, animals or the natural environment. Bear in mind that some essential oils are toxic to pets. If in doubt, seek professional advice. We accept no responsibility for misuse of the information we are sharing.
Hygiene is of course vital. To prevent ants from entering the home or to expel them, you can mix white vinegar half and half with water and use it to scrub the floors and to clean all the surfaces where the ants have appeared.
The smell of white vinegar and various essential oils such as peppermint oil, tea tree oil, cinnamon oil or neem oil are effective deterrents. You can make a spray by filling a spray bottle with water and adding a teaspoon or two of the chosen substance, and spray around where the ants have entered. Alternatively, you can soak cotton wool swabs in the substance and place them around the ant infestation. HOWEVER, PLEASE NOTE: many essential oils, especially peppermint and tea tree oil, are toxic to pets, so you should make sure pets do not come into contact with these substances.
Other methods include sprinkling used coffee grounds, pepper, Cayenne pepper, or cinnamon powder along the ant pathways, or spreading citrus peel around.
NOTE: We do not recommend killing ants.
However, for those who feel they need to, natural ant killer insecticides include borax, boric acid, cornmeal and diatomaceous earth. NOTE: diatomaceous earth has been associated with allergic skin reactions and lung problems in humans.
The Dalmatian chrysanthemum (tanacetum cinerarifolium) is a flowering plant which acts as a natural deterrent against many insects. Pyrethrum is an insecticide made from the dried flowers of the Dalmatian chrysanthemum, whose active ingredient is pyrethrin (not to be confused with the synthetic pyrethroid), which acts as a nerve agent. Pyrethrum is allowed as an insecticide in organic agriculture.
A PERSONAL EXPERIENCE: White vinegar as a deterrent, described by Nada Kozulić in Vitarnja on Hvar Island:
Ants are truly useful creatures, but are not welcome in the home. When they make their way into our living space, evicting them usually evolves into a bitter struggle, which is the more difficult if you don’t want to use chemical pesticides.
A few years ago, ants emerged from the ground to settle at the base of my front door, and proceeded to eat out part of the wooden frame to create a nest for the queen ant and her eggs. I tried various products to get rid of them and direct them to alternative lodgings – without chemical poisons – but nothing worked.
In the end I tried to remove them with a simple product which everyone has at home, alcohol vinegar, used as a spray. The smell alone was enough to send them scurrying off, and I sprayed both their nest and the pathway they took liberally. I repeated the spraying over two or three days, with the result that there were no ants at my door for the whole summer.
The following year in the middle of June I saw that they were starting to invade their previous nesting place again, so I repeated the alcohol vinegar remedy with the same result, the ants disappeared. For good measure I also spread around some pyrethrum powder. So the ants went off somewhere else, hopefully where they would not be a nuisance.
Information compiled by Nada Kozulić, Nicholas Haas, Vivian Grisogono 2022
