Little fire ants have made their way to two popular hiking spots and protected reservoirs.  

These tiny invasive ants with a painful sting are posing a risk to families and our ecology.

“The technology to have us see them in the real world is amazing,” said State Entomologist Christopher Rosario.

Ants so tiny, you need to zoom in several times on a cellphone camera to see them clearly. They’re aptly named the little fire ant. 

It's a serious invasive threat that continues to spread since they were first introduced to Guam in 2011.

Recently, it's been spotted at the Masso Reservoir Nature Park in Piti and at Sigua Falls in Yona, posing a risk to families.

Rosario said the Department of Agriculture was surveying the Masso Reservoir last October when they were greeted with the hidden pests. 

“We are on our second treatment. We wanted to figure out where the high infestation was, and really it’s in the public area where people come to rest and of course where the green waste debris is dumped,” said Rosario. 

Green waste debris illegally dumped at the protected area is a huge problem. 

“If people dump green waste debris in a forested area, chances are you are potentially infesting a whole forest, just like what you see here… Green waste is the biggest transport for little fire ants,” said Rosario.

Rosario made the discovery at sigua falls two weeks ago while hiking with friends

“If you’re facing the falls itself, it’s actually on the left hand side,” said Rosario. 

One of them met with a nasty surprise after laying on a rock. 

“He started scratching and felt like this itching sensation and still continued to scratch,” he said. 

They’re not to be mistaken for the more familiar tropical fire ant which are found in mounds of dirt. 

Little fire ants are often found in foliage and are significantly smaller, which he says makes them scarier.  

“Little fire ants don’t necessarily swarm on you, they fall on you. That’s the big difference– and the tropical fire ants are much bigger where you can actually see them,” he said. 

A treatment plan is underway thanks to a $1 million federal grant secured by agriculture. 

Rosario is working to eradicate the pests in the infested area using an insecticide baited with peanut butter, a recipe he shares for those who may have little fire ants in their backyards.

“You’re probably using about a tablespoon of insecticide. The majority of the mix is vegetable oil, peanut butter, and water to make it more emulsive and less thick,” he added. 

Meantime, he leaves this message to the community. 

“They should know that they shouldn’t be bringing any green waste material back. Like I mentioned, clean up after themselves, don’t leave any trash behind, and again be more aware of your surroundings and what you pick up,” he said.