Yes Dr.House
That's the excrements/excrement-residue. It's not really harmful. I've never had a L. niger founding colony whose cotton plug would not get that colour. So far 99% of the Queens were successful in spite of that.
Oki, Thank you! I'm glad to hear that :D
it's my first colony, so it's a little difficult to say what it is.
Hmm, and now i know what is meant with "niger" ... it's the wool after some weeks :D and the whole tube after some months :shock:
I'd say it is just excrements.
My queen is being a bit funny though because she seems to be tearing at the cotton wool at the moment. Maybe due to boredom if they are aware of that emotion.
Tearing at the cotton is common.
It might be just to soak some water out of it, trying to get material for possible pupation...many possible reasons. Don't worry, everything seems to be fine.
Yes Dr.House, a good definition of the species' name, lol