Thank you for coming so quickly!
These are wild carpenter ants living in an old log. They could just as easily be tunneling through your house. They are attracted to dark damp areas and as a result, are often seen around kitchens, bathrooms and around other plumbing. Even if you have an infestation, you may see the ants in the house for only a short time in the Spring - or not at all. If you look carefully, you may see some ants carrying larvae in this picture.