Why ants are declining

Everywhere ants are decreasing, even in Italy, where a double damage is recorded: native species are decreasing, while invasive ones are increasing, destroying the local ones, altering the balances of the ecosystems And they're definitely more aggressive. But where does the ant crisis begin? And what consequences can it have?

The causes of the decline in ants

There are several factors that are negatively impacting native ant communities. First, ants are very sensitive to temperature and humidity, and rapid changes can destroy entire colonies. The same goes for drought and extreme events, such as floods and fires. In short, the climate crisis is a silent killer of native ants. A second cause is the massive use of pesticides, which not only affect parasites but also beneficial insects like ants. Pesticides poison the entire environment in which native ant colonies live, as well as their food sources. Third, urbanization and the destruction of natural ecosystems reduce the space available for anthills. In general, ants live in the soil or in wood: when these environments disappear, they disappear too. Finally, heavy metals, microplastics and chemicals alter the soil, making it less suitable for native ant colonies.

What happens with the decrease in ants

We know well that ants are precious insects, even for humans, and have a great importance In the balance of ecosystems. Their decline has a series of negative consequences, such as the loss of vital functions for ants, such as these: 

• Aerate the soil
• Recycle organic substances
• Control other insects
• Dispersing seeds (myrmecochory)

The species most at risk

Not all native ants are equally at risk, and some are significantly more endangered. In particular:

• The living Leman ant in cool mountain environments and is particularly sensitive to rising temperatures.
• The lugubrious ant which builds large nests in coniferous forests and is a victim of deforestation. 
• The ant Myrmica sabuleti which suffers in particular from the abandonment of rural areas and the over-intensive use of pesticides.

The apocalypse in Fiji

A study published in 2025 in the journal Science analyzed the biodiversity of ants in the archipelago of Fiji using genomic techniques on tens of thousands of individuals collected in museums over the years. The results show that 79% of the archipelago's endemic ant species are in decline Over the past few millennia, and especially over the past few centuries, a trend that coincides with the arrival of humans, colonization, global trade, and modern agriculture. The study is important because it provides a precise and well-documented indication of what might happen in a world with increasingly fewer ants.

What can we do to help ants?

We can all do something to help and protect ants in our green spaces (garden, vegetable patch, terrace, balcony).

• Do not use insecticides against ants (unless you have a real domestic infestation).
• Limit herbicides that deplete the soil.
• Prefer natural methods (manual removal, selective traps).
• Use mulch natural (straw, leaves).
• Add compost.
• Avoid compacting the soil.

Furthermore, it is simply a waste, completely unnecessary, to destroy small anthills in the garden, as they are not dangerous and actually help natural pest control. 

Read also:

• Insect decline: 40 percent of species decline
• How to get rid of ants without using poison
• Repel flies without pesticides