I found a used ant farm for sale, sans ants, at a yard sale. Lack of ants was easily remedied by digging up a fire ant nest (native, not one of those invasive monsters), finding the queen, and plonking her in. Had my own little fire ant colony in our dorm room. Laying eggs, raising pupae, and so on. It was awesome! Far better than the sterile colony that must have originally lived in it.
Keeping moisture levels was a bear. Got it too damp one time and they all died of some fungus.