Ways of improving success
At one time all swarms were what I call "natural swarms", that is they were genuine attempts by the parent colony to increase colony numbers. Most books and advice are based on this and in the past it was very easy to hive swarms and manage them. It has become more difficult, with failure being common. For the purposes of this page I will ignore hunger and mating swarms.
Naturally, prime (first) swarms are headed by fertile queens, casts (second and subsequent swarms) have one or more virgin queens. In the past if a swarm or cast was hived, it would build up on its own, rarely needing any attention for the rest of the season, apart from the odd inspection. Fertile queens would always start laying within a day or so and virgin queens would get mated and be laying within 10-14 days. It was very rare there would be any queen failure, but that is only to be expected, as that was their only means of colony reproduction.
Unfortunately since the turn of the 21st century I have observed the character of many swarms has changed. There are still the natural swarms, but there are many that aren't natural. Mainly as a result of the queen problems that many beekeepers are now having, there are swarms with failing queens and prime swarms with virgin queens.
All beekeepers need to be aware there are likely to be these problems, look for them and deal with them. I often hear that a swarm is queenless, but I doubt if it is. It probably has a failed queen in it that has gone off lay. All you need do is to to remove her give it another queen.
When taking a swarm, have a close look at it. If it looks healthy, then you should be O.K., but so many look sick and may need treating.
Apart from the above there are two main perceived problems with taking in stray swarms and hiving them, often to the point where beekeepers, especially beginners are strongly advised not to. These are:-
As these "problems" are so easy to deal with I always advise taking swarms, especially by beginners, as there is so much to learn.
If you know the hive a swarm has come from and it is free of foul brood, then it is O.K. to hive it on comb, but if you collect it from an unknown source I think it is worth taking precautions.
A swarm takes a supply of nectar/honey with them. If this is infected with foul brood, they will store it in comb if that is what they are hived on, so keeping the infection going in the new colony. To greatly reduce the chances of infection I advise hiving a swarm on foundation and not feeding for at least 3-4 days. I rarely find swarms need feeding anyway, so I don't do it.
An added precaution is to hive a stray swarm some distance from your existing colonies, especially if you do hive it on comb. If there is a problem with foul brood there is less chance of infecting other colonies. When it is shown to be clear it can be moved.
There is much advice on hiving swarms, but I rarely have the problems that others seem to have. The most common problem is absconding, which is easy to overcome. Here is what I do:-
The swarm should settle down now. Even if it decides to abscond (this rarely happens with me) with a clipped queen, you will find it close to the hive, probably on the front or underneath, so you haven't lost it.
You will have probably noticed this is much easier than the advice that is often given. Even books going back over 100 years often advocate hiving in the evening. Why? There is no need to if you do what I suggest. I hive swarms at any time of the day, often as many as three in a day, where I have collected them in the same skep and hived them quickly, so I can collect another.