So I have noticed something consistent with almost every leptogenys colony I have kept. This fungus appears. And it grows on dead workers.
It looks remarkably similar to a fungus that kills ants (not quite cordyceps) the local one grows from the cracks of a live ant's gaster, eventually killing it. Now I haven't noticed any growing on live ants, but colonies always seem to stop growing, and this fungus appears in abundance. So what should I do? My leptogenys did very well for two months, but began dipping in numbers these few weeks.
