when you find the queen, you should have no doubt about it. even out of the variety of the ents(workers, warriors, etc), she still is quite recognizable due to her size as compared to the rest of the specimens. assume that she's extremely obese, say by a ton or so as compared to all the rest of the ents at that colony. although the question is how to lure her may indeed be somewhat of a problem. i'd imagine that she might be the very last one to come out, or not at all(unless you're planning to simply dig in to their colony.