94. Another cause of swarming is insufficient ventilation, depending upon the strength of the colony and the outside temperature. Bees create air currents through their hive to keep the temperature in hot weather not higher than approximately 95° F., and incidentally these air currents serve to evaporate the excess water from the nectar. Usually an entrance the width of the hive and 7/8 of an inch deep will be required by the beginning of the main honey flow. The methods of giving additional ventilation vary, but additional ventilation is absolutely necessary in quite hot weather. Perhaps the best method is to raise the front of the brood chamber about half an inch off the bottom board by inserting blocks of wood. Some stagger the supers so as to leave small openings between them but this is hardly advisable in the production of comb honey, as bees do not work so readily in sections where the light strikes them. In any event, the giving of additional ventilation should be handled in such a way that it does not afford an opportunity for robbing if the honey flow is likely to shut off suddenly. Care must also be taken to reduce the ventilation after the heat of the season to prevent robbing.

95. Lack of shade is frequently another cause of swarming, probably because it is difficult for the bees at times to maintain the proper hive temperature unassisted. If metal covers painted white on top, with inner covers, are used, allowing an air space between the covers, and if good ventilation is given, lack of shade is not an important cause of swarming except in the hottest parts of the United States. In such localities it is advisable to place the bees under trees or other shade, and if necessary, to provide artificial shade for the colonies at least during the hottest part of the day.

96. When bees cluster on the outside of the hive it is, under normal conditions, a sign that something within the hive is radically wrong. It may be an excess number of young bees in the brood chamber, lack of room for the queen, insufficient surplus storage room, or lack of ventilation. When you find bees clustered on the outside of the hive, look for one of these incorrect conditions and remedy it as soon as possible. Even then the bees may be reluctant to go back to work. Under such conditions some beekeepers have found that if they shake the bees off a number of the combs from the brood nest in front of the hive this "loafing" habit may be broken up, if the conditions which caused it have all been removed. See paragraph 111 on how to shake bees off combs. It is far better to anticipate every such condition if possible, in order to control swarming. Not the least important of all these measures is adequate brood space for the queen, accompanied by adequate storage space for surplus honey at the beginning of the honey flow. Frequently if these conditions are given until the colony has gotten well started on the honey flow, swarming will not be started during that honey flow.

97. Clipping both wings on one side of the queen is often practiced to record the age of the queen and to prevent swarms absconding. The queen may be clipped on the right side if she was introduced on an even year and on the left side if she was introduced in an odd year, and in that way the beekeeper can tell at a glance the age of the queen. This does not control swarming in any way, but is an aid in hiving swarms where they issue despite control measures. Fruit bloom time in the spring is the best time to clip queens. The queen should be carefully grasped by the part of her body to which the wings are attached (thorax) ; as any other parts are soft and likely to permanent injury if mishandled. (See figure 30.) Take a sharp pair of scissors and clip both wings off one side close up so that the queen will not be able to fly. This can easily be learned and the beekeeper may practice on drones if he wishes, as drone bees are worthless and cannot sting. Another method is to pick the queen up by the wings with the right hand, transfer her to the left hand by grasping all of her legs on one side of her body between the thumb and first finger of the left hand. This leaves the right hand free to clip off the two wings on either side. She should not be handled more than is absolutely necessary, both because she is easily injured and if handled too much may be killed by the bees when she is put back into the hive. Honeybees have two pairs of wings.

98. You will now see the value of clipped queens when you have to hive a swarm that may have issued in spite of your control measures. When the swarm issues, the queen will usually be found either on the front of the hive or on the ground in front, surrounded by a few of her bees. She may be put into a small homemade cage such as illustrated in figure 44. The hive from which the swarm issued may then be moved off its stand a few feet and another hive previously prepared for the bees put in its place. Any supers on the hive from which the swarm issued should immediately be placed on the new hive. The cage containing the queen should be placed in the entrance of the new hive in such a way that direct sun will not strike her. The bees in the air or clustered on a limb will soon discover that they have no queen and will return to the exact location from which they issued, hiving themselves in the new hive without any effort on the part of the beekeeper. Under normal conditions the queen may be immediately released among the bees when they are going into the new hive rapidly and she will go in with them. If the bees form a cluster and do not come back promptly, take the new hive with the queen in the cage to the cluster and hive them all in the regular way. When a swarm clusters in more than one location where it has issued from the same hive, it is usually a sign that there is more than one queen with it. Normally, remember only the old queen issues with the first swarm. Subsequent swarms, or after-swarms, will be headed by virgin queens. Abnormal weather conditions may have caused the bees to delay swarming until the young queens begin to emerge, then one of them may accompany the swarm with the old queen at the time it issues. Where two or more small clusters are formed from one swarm, they may be all hived together without regard to the probable number of queen because all but one queen will be killed within a day or two.