I don't think this is a production quality issue, I think this is strictly materials used issue. Not all materials are good for all ants. I'm curious to see if they've run into this problem with other people and I wonder if they were all pretty destructive species of ants. It becomes problematic and I wonder if a disclaimer should be involved with the purchase of these formicariums.
I tend to agree. These plugs do come in the Camponotus kits I purchased. Thing is there are many accessories, including the Out World that appear to be made of the same material.
Really though it's all speculation until I hear for AC.