There is also a way of increasing your hives by doing what's called "splitting" them. This is done when as Mindy has described, the bees are making queen cells & you see the hive has an extraordinarily large population of bees. You can order young queens. They come in a small wooden box which has screen so she gets air etc... there is a hole at one end which is filled with "candy". When it arrives there is a cover over the candy which you later remove so the candy is exposed. You open the "overcrowded" hive & remove some of the brood frames & put them in a super along with some filled honey frames & some empty frames. Then you place that super on top of several layers of newspaper on top of the overcrowded hive & place the new queen in her cage in the "new" super. Then you put the hive cover back on. The bees from the bottom, overcrowded hive will eat through the newspaper to get into the uppermost "new" super where they find the new queen in her cage. At this point, if the new queen were loose the bees might kill her as an intruder or she & the "old" queen would fight to the death if you didn't have a queen excluder on the brood section of the older, established hive. When you have enough bees in the new super then you take it off the original hive & move it to it's own location. Now you will take the protective cover off the candy filled hole. The bees in the "new" hive will eat out the candy & release the new queen who by now they have had time to accept & get used to. Viola' --- new hive.
