You don't need to worry about fire ants in your location. At least, not YET, lol! But to answer your question...they are normal sized small ants. And not very pretty.

Fire Ants have made it to southern Tennessee/Maryland but not to Massachusetts, yet. Carpenter Ants are large and black, but there are many species of ants, none of which, except the Fire Ants, are either a threat or harmful to us and for that reason there is no good reason to do anything to control them unless they are inside our houses.

Perhaps a velvet ant? But which is actually a wingless wasp, one that has a nasty sting.

I've seen some really bright red ants around here the last several years. They seem to move their nests a lot, that's when I first noticed them - a whole sea of them marching up the driveway, surrounding my brother's feet, never a bite from them. I guess they are just normal ants that happen to be bright red. Some sort of defense against predators maybe?