Before I start, I should add that breeding captive ants is not possible in most species, and when it is possible, it is often in invasive ants. Related to that…don’t keep invasive ants. They’re invasive for a reason, and you don’t want to be the one responsible for creating a local (or even worse) epidemic of ants.
There are several ways of acquiring ants: 1) Catching newly mated queens; 2) Digging up an established colony; 3) Ordering them from a webshop; 4) Buying from/trading with other ant-keepers.
1) Many species of ants have a nuptial flight. After this flight, one can pick up mated queens from the ground (easily distinguishable from the non-mated ones by their lack of wings, which they just discarded). Once you have caught individual queens, you can put them individually in a tube. This tube should contain a freshwater reservoir, which has been plugged with a cotton ball. The end of the tube should be plugged with another piece of cotton, in order to keep the queen from escaping (while still letting some air through).
To prevent unnecessary stress to the queen, one can darken the tube (I normally wrap it in kitchentowel, which you can easily remove to check up on the queen).
2) You can dig up an entire colony (including the queen). For some species this is very easy (Myrmica rubra comes to mind), for others, it’s extremely hard. Some Lasius species for example have satellite nests, which can be far away from the nest itself. They can put the queen there, in which case she’s basically impossible to find (within a decent time-frame). Also, some species nest in wood or rocks, making it very hard to find the queen (without accidentally crushing her). I personally don’t recommend digging up colonies, as it’s a very destructive way of going about. Not only will many ant workers be left behind, you’re also damaging the environment itself by digging a big hole. If you do plan on doing this, make sure you do it in an area where it’s actually allowed to dig!
3) Aaah, the (in)famous webshops. I am not entirely sure how the system works in for example the USA, but in Europe you can send ants to different countries. This gave rise to different webshops. Unfortunately, many of them sell tropical species as well, for which they didn’t get a permit (the owner of Ants-Kalytta was caught and fined in Australia for trying to smuggle ants from Australia to Europe). This kind of practice should definitely not be supported in my opinion.
However…I still want to mention webshops. For a starting ant-keeping hobbyist it can be hard trying to make a nest etc. Webshops such as http://www.antstore.net don’t only sell ants, but equipment for keeping them as well. Some things, such as fluon (used to prevent ants from escaping) are, as far as I know, hard to come by in small quantities. If you’re serious about ant keeping and don’t just want them to walk around and dig a hole (and die not long after), don’t buy the commercial AntWorks.
Furthermore, if you don’t want to wait for the next mating flight, they tend to sell very easy to keep species as well, such as Lasius niger. You can easily catch around 500 of these queens yourself on a good mating flight, but at least the option is there.
4) Buying/trading with other ant-keepers. I personally don’t have any experience with this, but I do know people that collect a lot of queens during mating flights, and give them away afterwards (or sell them for a small amount). For Dutch/Belgian people, there is www.antforum.nl. They also have many so-called ‘caresheets’, which describe for many species how to best keep them (temperature, humidity, food etc.).
So now that you know how to get ants…next time I’ll explain how to actually keep them.