Stubborn spiders in your home? One whiff of an insect rival can leave them feeling antsy

Aggressive ants could hold the key to keeping household spiders outside, a new study has found.

Scientists are  now one step closer to launching a product that is proven to keep spiders out of the homes of arachnophobes.

A study, by Simon Fraser University in Vancouver, has found that common spiders, including black widows, false widows and hobo spiders, avoid areas that have been swarmed on by European fire ants, known in the UK as red ants.

Researchers believe that the ants leave a chemical in their wake that, if identified, could plausibly be replicated, bottled and used as a repellent – if tests prove it is safe for human use.

Andreas Fischer, the lead author, has been searching for a repellent that isn’t as harmful to the environment as pesticides, after his previous study proved that natural methods including chestnuts, lemon oil and mint oil, which are the most recommended on Google, do not work.

He told The Telegraph: “We found indications in literature that when the number of ants in an area goes up, the number of spiders goes down. For us that was indication enough to say ‘hey, let's test it’.”

Mr Fischer’s team took four species - all female - of common North American house spiders and three different species of ants from the area near their university campus.

Each species of ant were then let loose on filter paper in a cage for 12 hours before being removed and replaced with each spider.

The majority of spiders steered clear of the filter paper previously trampled on by the red ants (Myrmica rubra), the study showed.

A fourth species, the cross spider (Araneus diadematus), showed a similar trend, but this wasn’t as clear.

“We found that these European fire ants, which are really aggressive, and it seems aggressive enough that all tested spiders had an aversion effect to chemicals deposited by these ants,” said Fischer.

While ants and spiders might not seem like natural enemies, Fischer explained that a spider would not stand up against a swarm of territorial ants.

Fighting the ants “takes a lot of energy and focus and nutrition, and can cause severe stress” on spiders, he said and added: “Thousands of ants will easily outcompete any individual spider.”

“There is a real interest for spiders, in general, to avoid infested habitats by about a few metres and settle somewhere where fewer ants are.”

While the study is a promising sign that a product may one day be available, Fischer stressed that people should wait for further tests and not bring ants into their home, which are “more dangerous than any spider you have in the UK”.

The paper is published in the journal Royal Society Open Science.