Vague question I know, and no picture, but educated guesses?

[Batspiderfish]

but, they may be an exotic species!!!!

Indiana has no invasive ants. SpeciesK and I both live there.

There are isolated pockets of Monomorium pharaonsis and Paratrechina longicornis, but this wouldn't necessarily constitute "invasive".

Sadly, this description does not tell us much. The only local ants which are small enough to be ~1mm are
Cardiocondyla obscurior, Strumigenys, Brachymyrmex depilis, and the Solenopsis thief ants -- all of which are pale or brown. At slightly larger, Hypoponera opacior might be a candidate. You're sure it's 1mm, right?

[Martialis]

Really? We have P. longicornis and M. pharaonsis? Also, are you sure about C. obscurior? They're Asian ants.

[Batspiderfish]

Really? We have P. longicornis and M. pharaonsis? Also, are you sure about C. obscurior? They're Asian ants.

Tropical species can survive winters when they nest inside or close to buildings. Both of these species have been found in Indiana. In Maine, I've stumbled across Hypoponera that were living in an old rail station (native to the US, but not in Maine.)

[Martialis]

This is true. Thanks for telling me of their presence.


No, I don't intend to risk introducing them to another area.

[SpeciesK]

I will have to look those up to look at them. I am sure of the size but not much else. I suppose that unless it was a fertile queen ant that having one of them won't make much difference unless there is such a thing as solitary ants. And even then I guess.