thanks for the replies, gents! i'm kinda perplexed as to the size of the colony i'm housing, since most ant colonies cannot survive without the queen...i hope i dont find the ugly beast....ick!
stickboy: thanks! that will be my second resort, just because i'm worried about killing the stressed tree.
TB: yes i'm fairly sure it's a new hole, bacause there was a little ledge of torn bark underneath where the hole is now, and the ledge was covered in the "sawdust" the ant's burrowing made. that combined with the dead leaf makes me think that they're hollowing out my branch.
clrosner: that's a damn good idea! and it kinda sounds fun!
i'll let ya know how it goes.