I currently have a Tetramorium immigrans colony housed in a small AntsAustralia Acrylic Nest. I am using a small 3" outworld from THA to place food in. I decided to use vegetable oil as a barrier, as it's clear, so I could still have a good view. It's been about a week since the move and everything's been fine until today.
I woke up and went to check on them, and at first nothing was out of the ordinary. There were about 6-7 workers foraging, yet were ignoring the mealworm and honey I had placed in there. Then I noticed 2 dead workers and 1 dying. I wasn't surprised at this, as they were nanitic workers, and were probably around 4-5 months old at this point. Then I looked closer, and the live workers were acting strange. They were walking strange and a couple were dragging their antennae. I also noticed one was able to cross the barrier (luckily there was a lid to the outworld). I quickly replaced the oil barrier with a baby powder+rubbing alcohol barrier. I managed to get a video of them. The queen, brood, and workers in the nest are still perfectly fine.
What's wrong with them, and how do I fix it? Note: the live workers in the video are still young and shouldn't be dying of old age.