Immediately suspicious, Mr Morrison collected the ants from his Ulladulla garden and sent them off for identification.

Last week he received the news he was dreading: they were indeed Argentine Ants - one of the world’s worst pests.

The ants have been virtually unseen in Sydney or the South Coast since they were the subject of a highly publicised eradication campaign that ran from 1950 to 1983.

Mr Morrison is concerned that his find could indicate the formation of a new colony in the Ulladulla region.

He said the Department of Primary Industries told him is was unlikely the ants would be of the Argentinian variety.

“They were very surprised when they discovered they were here in Ulladulla.”

After researching the ants and talking to department insect experts, Mr Morrison has loads of information about detecting and getting rid of the ants.

He said the ants were very small, only about 2mm in length, and highly invasive.

“They’ll get into anything, even sealed fridges.

“Once they make a nest, they keep branching out making new nests, to eventually form a massive colony.

“They are very nasty.

“They compete with native ants and are a real pest to humans,” Mr Morrison said.

He has purchased strong ant baits from Sydney to control any future invasions and has warned people living in Ulladulla to keep an eye out for the pests in the yard and their homes.

“There have been a lot of ordinary ants around, but these are only about half the size of black ants.

“If people think they have found a nest they should collect some of the ants and send them off for identification.”

Mr Morrison said he remembers the eradication program run by the government many years ago that paid kids to catch and send off Argentine Ants.

“They were a real problem and I’d hate to see that happen again.”