A few days ago I caught the ant in the test tube. I think it's Myrmica Rubra. Yesterday I caught another ant that looks very similar. So I thought it was Rubra and as I read that they are polygynous, I put them together. They didn't fight, when they met they stressed a little but after some time they just stood facing each other very close but without any signs of aggression.
They spent the night standing like this in the small arena outside the test tube that I gave them, but then I noticed that they look a bit different. The new ant is overall darker, has a darker gaster and is a tiny bit smaller. I separated them and the original Rubra queen immediately went back into the test tube. Does anybody recognize these species or are they the same and I can put them together?
The first ant:
The second ant: