It was quite a weekend dealing with these Houdinis. Due to humidity trapped in their foraging container by a poorly ventilated lid, these ants were able to climb easily on the fluon I had applied. I even saw one walking upside down at one point. They couldn't get out while the lid was on, but accessing them was getting increasingly difficult as their numbers keep climbing. I tried renewing the fluon and leaving the lid open, but over time I started to notice ants had climbed past the fluon and out. It seems that vertical surfaces with fluon may slow them down a bit, but their grip is such that eventually they find ways up. I got pretty discouraged by this really, but I didn't want to give up, so I tried a new open top lid. This lid lets out the humidity, but the ants can't climb upside down to exit - at least for now!
The flip side of this set-back is that the colony is absolutely thriving. They launch big feeding frenzies for any protein.
I think they just have a strong instinctual urge to explore wide distances. I know these ants set up wide ranging satellite nests and use long scent trails. I think I might try to work with this instinct by giving them several out worlds connected by long tubing so they can really roam. Something tells me this won't be the last time they find a way to escape, though!