Wow this is really cool! I have heard of the ant-toilet before from Antscanada, and my Lasius Niger colony sort of does this by making little excrement piles in their outworld from themselves and the brood, but I haven't seen much of this online either. Weird!
Does your Messor colony have many brood yet? I haven't seen much in the images but your colony looks like it's doing super awesome either way!
Yeah, it is awesome with the toilet.
It really works.
The toilet is now in the front right corner of my Antcube, and it is used a lot, and it is a great place for me to clean (but never clean it completely, otherwise they won't recognize it so well anymore).
As you can see in my latest posts from yesterday, yes, I do have brood, they have distributed them in 3 different chambers, according to size, development, heat an humidity (I assume). I think they are doing fine, but I do limit their protein a bit (only around 3-4 times a week) to keep the colony from exploding. I am happy with how it is right now.