Recently, I noticed that they were making a bit of a comeback. They had two pupae (in cocoons). However, I noticed that one had been neglected and left just before the next entrance. I checked on them later, and the cocoon was in a small lid containing honey. I immediately knew that it was probably dead, so I opened it up with a razor blade. I saw that it was still a larvae, but more importantly it's cocoon was infiltrated by springtails. Because of this I'm wondering wether the springtails had killed the pupae, and so the ants dumped her. I'm just wondering if anyone else has had any experience with this.