I've thought about that question myself, and the only situations I can think of going on right now, in order of greatest to least likeliness:
A) They have, and have it planned.
B) They have, but don't have any plans until it becomes more vital to their survival.
C) They haven't, but are starting to individually consider it now.
D) They haven't, and don't plan to.
I think they have it planned only because I can't see when it wouldn't be more vital, they're both doing very poorly. They need better teamwork, though a merge won't guarantee that, but it's their last option as I see it.