Did you know snails actually breed more than rabbits?

This may seem quite surprising for a species that's not exactly known for its pace, but one pair of common white snails can produce about 400 offspring a year.

Millions of common white snails were detected and destroyed to protect crops in southern NSW. ( Supplied: Riverina Local Land Services )

That's why an outbreak of the pest has sparked concern in southern New South Wales.

Millions of common white snail — not to be confused with the regular garden variety — made their home on a vacant 20-hectare block of land on the outskirts of Wagga Wagga in the Riverina.

Stopping snails in their tracks

Snails can spread via machinery and vehicles, posing a biosecurity risk for farmers. ( Supplied: Riverina Local Land Services )

To combat the pest Riverina Local Land Services (LSS) coordinated a controlled burn of the site by the NSW Rural Fire Service and Fire and Rescue NSW.

"It's a numbers game, like with many pests, so we want to kill as many as possible in one go," Riverina LLS agronomist Lisa Castleman said.

Given the chance common white snails will take up residence in crops, silos and even on machinery.

"Snails are moist and sticky and their shells break up into many pieces," Ms Castleman said.

"Someone might go to a French restaurant to eat snails, but you don't want to find some snail in your loaf of bread.

On their own they can't travel too far — in wet conditions they can only move about 200 metres in a month.

But these snails are great at hitching a ride.

"They will climb up on to a truck an onto the undercarriage, particularly when it's wet or when it is dark," Ms Castleman said.

"That's when they are trying to find a place to catch a lift."

Grain industry's reputation at risk

Alan Brown, who farms at Borambola near Wagga Wagga, said the risk they pose to the grains industry can't be underestimated.

"It's got potential to cause some real problems," Mr Brown said.

"As excluding them from grain is almost impossible once they are present in the environment."

Fire is the most effective way to deal with snail outbreaks in sites where baiting is not possible. ( Supplied: Riverina Local Land Services )

"We have to take action to make sure they are not there, so that's another cost we have to bear, and we don't need that."

Ms Castleman estimated the cost for grain growers to eradicate would be more than $45 a hectare if they became endemic.

"They are not endemic in southern New South Wales, but it would cost our industry millions if not more and it would be ongoing, she said.