Thanks for the question.

These are NOT termites so nothing to worry about. They are a species of ant although I cannot give you precise identification. I suspect that the ants you are seeing are coming into your house because of its warmer environment. While there are Minnesota ants that can nest inside a house, if this was true in your situation I would have expected you to have seen the presence of ants inside on a frequent basis during the summer. I assume that you did not. Here are some sites that provide information about common Minnesota ants:

https://extension.umn.edu/insects-infest-homes/ants

https://files.dnr.state.mn.us/mcvmagazine/young_naturalists/young-naturalists-article/ants/ants.pdf

Basically there are three main groups of ants: sterile females known as workers; winged males that live for a short period of time and whose sole purpose is to mate with queens; queens which are fertile females that develop wings only when ready to mate.

So right now most of the ants, at least the ones you killed, are workers. The winged ants you are seeing are either queens or males. Once they have mated (often about this time of the year, late September 2024), the queens go off somewhere and stay until it is time to lay eggs. Depending upon the ant species, this egg laying could either occur now or in spring 2025. The winged males die right after mating.

At this moment, the ants in your house are just a nuisance. They are harmless with respect to either humans or pets. Keep killing them with a spray. The workers will soon die on their own. A vacuum cleaner could also be used to suck them up. I would guess that within two weeks, you will observe a significant reduction in the ant population. If perchance there is an ant nest inside your house, evidence of this will be the observation of ants into the winter months. Should this occur, start using ant traps that are available in most hardware stores.

Good luck. Get back to us with any additional, related questions. Thanks for using our forum.