Odd black residue ! (poop? Why there?)

[Barfdog]

Okay,

In my Veromessor Pergandei's setup I have her and her workers in a test test with a portal connected with a sugar and honey water tube.

After a day or two there's trash moved into the test tube and portal with an odd black residue on the cotton of the sugar water test tube.
I'd imagine if it was poop then they'd know the test tube was sugar water but why are they putting trash there? I've also never seen them drinking from it as well, but they are a very young colony. So what could this black residue be? Why would they put it in the sugar water test tube? Or could it be some kind of mold, but no actual mold is ever present in there sugar water tubes because I regularly change them. So what are these black specks!
Thanks AC Fam

[Aquaexploder]

It could very well be poop but pictures would definitely help to identify. But yes, based your description it sound like poop. As to why they put it there, they may need more space, so the only place they can put it far away enough from the colony is there.

[Barfdog]

It could very well be poop but pictures would definitely help to identify. But yes, based your description it sound like poop. As to why they put it there, they may need more space, so the only place they can put it far away enough from the colony is there.

I figured it was probably poop. I just think it's odd for them to put it there I guess and I'm also noticing that small colonies do not clean up very well. Anyways thanks for the input. If this particular colony keeps doing it I'll post a picture of it.

[Aquaexploder]

No problem.