I know they do dig. But he iis like none stop digging. My colony has not breed yet and I think the colony is to young they are only like 3 months old and the one that is digging is a male at might be the Alpha male at that
Don't worry about it. They do it for all sorts of reasons such as looking for food, and because they are trying to make a spawning site. You said that they are young but they are probably trying to practice anyway.