Two bites of a muesli bar was all it took for Deanne Cook to feel like she was on fire.

The Karratha resident quickly realised it was not just the snack she was eating but dozens of tiny ants.

"It was like I was on fire. I was in the shower sobbing," she said.

"I didn't even knowing what had happened until I went back to the pantry and saw the carnage.

A colony of Singapore ants had attacked her food, in some cases chewing through sealed packets.

"Fiery, little tiny zillions of ants just covered me," she said.

Ms Cook took some antihistamines for the bites but her face badly swelled up and she was forced to take a day off work.

Singapore ants crawling throughout Deanne Cook's Pantry ( ABC News: Kendall O'Connor )

She said she looked like Rocky from the 1980s movie 'Mask.'

"It gave me the heebie jeebies. I opened the cupboard and closed it again. Everything will have to be thrown out and fumigated," she said.

"There were a lot of foods we were keeping in the fridge, such as cereal, knowing that these ants are around. But I didn't think about the (sealed) muesli bars."

The Singapore ant is not generally considered dangerous. ( Supplied: PaDIL )

Ants can pose fire risk

Department of Primary Industries and Regional Development entomologist Marc Widmer said Singapore ants were an invasive species to northern parts of Australia and were not considered dangerous.

But he said Ms Cook was stung in a very sensitive area.

"They have a venom gland associated with the sting, it's a natural defence and pretty much their only defence," he said.

"I've been stung by thousands of Singapore ants and I consider them virtually innocuous compared to other things that can sting, but I would hate to be stung in the mouth or in the eye certainly."

Mr Widmer said the ants had an appetite for bread, fats and oils and would chew through plastic to feed.

"They eat people's eskies, thongs and wiring in the cars and they're just a real nuisance," he said.

Dozens of ants were found in Deanne Cook's pantry ( ABC News: Kendall O'Connor )

Mr Widmer said their appetite for plastic could result in them eating electrical wires.

"They get into plastics and can chew the insulation plastic off electricals and they can cause fires."

"If you see them in your pantry it's a bit of a wake up that they're likely to get into your food products and recruit more."

Deanne Cook said she hoped her unfortunate experience served as a warning to others across Northern Australia.