no idea, but good growing! i got a little division of this last summer, and so far not doing so good... it arrived with all but 2 of the leaves knocked off, and it is just not growing, although is did root into the new tree fern pot. i have moved it to face more light, it was too shaded. yours looks nice and green, and the yellowing bulbs is normal i understand... how much sun are you giving yours? i think ants are supposed to like this one, the bulbs are hollow and they can nest inside them. i don't know if there are natural openings in the bulbs to help the ants?