I have a number of colonies that I feel will soon be overgrown. I prefer my colonies on the small to medium size, but I have a Tetramorium colony that will soon be reaching epic proportions if left unchecked. Don't get me wrong, I don't mind large colonies, but I have a Camponotus colony that reached "scary" size last summer and I considered letting them forage outside to relieve some of the congestion. The challenge of coming up with a queen excluder that would still allow majors to come and go was just too great, so I added an outworld instead to solve the overcrowding problem. I'm thinking that I might let this Tetramorium colony out to forage because I have a screen that those persistent little workers will find their way through, but I know a queen can't. I always wanted to do this with a colony and their numbers might be "thinned" by natural means.
On the other hand, I grow bonsai trees and am very familiar with the thinning and pruning that's required to keep them small. The tree is allowed to grow, and that new growth is then pruned away, encouraging new growth and this keeps the tree vibrant and healthy. I propose doing something similar with an overgrown ant colony. Once a batch of larvae has pupated, an equivalent number of mature workers would be removed before the pupae/cocoons eclose. Essentially pruning away the new growth to keep the colony number the same, in balance with its housing and environment. Don't worry about the how and humaneness of it right now, just consider the concept. I feel I'm in a position where I have to do something, or I won't be able to risk an outbreak which somehow seems inevitable if the colony keeps increasing the way it has been. Already there have been serious attempts. I've read that we're not supposed to release colonies back to the wild (this one came from my garden) so if I can't keep them to a manageable size, I'll have to destroy them all. What other options do I have?