Okay, where is the boundary drawn between animal care requirement questions on Biology (like How should I feed and keep an ant queen?) and this site? Is there some overlap? I know some questions (identification, for instance) are on topic on both Gardening and Biology. Is that the case with animal care questions on Pets?
Yes, as they relate to 'pet' ants, like an ant farm (formicarium) in a home. The question on biology How should I feed and keep an ant queen? focuses around a captured wild individual so that Might be out of scope. A purchased ant farm with domesticated ants would definitely be in scope.
As a site we have not addressed the question; of questions about captured wild life being domesticated by the person who captured them, given the responses on the very few questions that lightly touch around the subject I suspect we as site would define them as out of scope, should we be formally asked.
So yes questions about ant farms are on topic at pets, the specific question you reference at biology would most likely be out of scope.
I posted the question Are there native web building spiders in North America that can be domesticated? which tests several scope issues; as it addresses the domestication of a native insect. It did not get a lot of support or negative attention. So barring some change, both insect pets and domestication of wild species would seem to be in scope.