How big does a colony get, and how many ants come with one when it ships?
It depends on the species, and the range is wide. Some colonies stay small for life; others grow into the tens of thousands.
At the small end, acorn ants like Temnothorax curvispinosus nest in acorns and twigs and keep a manageable colony size. Many of the ants we keep, such as the Chestnut Carpenter Ant (Camponotus castaneus) and the fungus-farming Trachymyrmex septentrionalis, reach thousands of workers when mature. At the big end, Crematogaster cerasi colonies can reach tens of thousands.
Every colony starts the same way: one queen raising her first small batch of workers. Depending on the species, that first batch takes two to twelve weeks to arrive (How Long Until My Queen Has Workers?). After that, growth speeds up, because the workers take over foraging and brood care.
The colonies we ship come with their queen and, for most species, around 5 to 20 workers. We don't sell queens on their own: we raise them through founding first, so you get a colony that is already working (Why We Only Sell Queens With Workers).
If size matters for your setup, each species' care guide covers how big the colony gets and what nest it needs as it grows.