State agriculture officials are inspecting a Mililani Mauka neighborhood where a little fire ant infestation was discovered.

It is the first residential area reporting an infestation on Oahu.

Six homes in the neighborhood in the 95-1000 block of Auina Street were treated with pesticides, an Agriculture Department spokeswoman said.

The infestation was discovered by a homeowner who brought in an ant sample for testing on June 18, said Janelle Shiraishi, the department spokeswoman.

When the test came back positive, the home was treated and an adjoining parcel was surveyed.

Other homes in the area that tested positive also were treated.

Agriculture officials canvassed the neighborhood Friday, leaving bait traps to determine the extent of the infestation, which some neighbors said has been a problem for several years.

Little fire ants have been found on Hawaii island since 1999, but in December 2013 they were detected on Hawaiian ferns at stores on Maui and Oahu. Small infestations at five Oahu nurseries, three of which were in Waimanalo, were treated and the ants were eradicated.

In May, a small infestation of little fire ants was discovered at a Wailea hotel on Maui. The area was treated with pesticides.

Little fire ants, measuring about a 16th-of-an-inch long, are pale orange in color and can cause painful stings.

Suspected invasive species should be reported to the state’s toll-free PEST HOTLINE – 643-PEST (7378).