46 Farmers’ Bulletin 1198. 
Colonies in hives which are well ventilated and well protected from 
the direct rays of the sun are less inclined to swarm than those in 
poorly ventilated hives exposed to the sun. Ample ventilation should 
be provided, hives should be painted white, and if the weather is hot 
during the swarming season shade-boards should be used over the 
hives. 
Distribution of bees within the hives—Probably the greatest single 
factor in the cause of swarming is a congestion of unemployed bees 
within the brood-nest or discomfort in this part of the hive from 
overheating and lack of ventilation. Colonies which build a barrier 
of sealed honey around the brood-nest during the spring, thus con- 
fining their activities to this limited space, may be inclined to swarm 
even when there is an abundance of empty comb in other parts of the 
hive. 
When the bees increase brood-rearing in the spring so rapidly that 
young bees accumulate faster than they are able to take up work in 
the hive outside of the brood-nest, the tendency to swarm is usually 
strong unless there is a dearth of nectar at this time. This condition 
brings on the normal swarming season, and great care is necessary to 
bring about a better distribution of the bees to prevent crowding the 
brood-nest. 
If to this condition there is added any factor which in any way 
interferes with the young bees leaving the brood-nest to take up work 
in the supers, the congestion of bees within the brood-nest is in- 
creased, since this condition causes field bees to remain within the 
hives when they should be at work in the fields. The giving of super 
room of such character and in such a manner that the increasing 
number of hive workers may be enticed from the brood-nest and 
given work to do in the supers is of the greatest importance in the 
prevention of swarming. 
If anything causes the field bees to stay in the hive during the day, 
the congestion and discomfort are greatly increased and these idle 
field bees may become a serious factor in increasing the tendency to 
swarm. In nature when a swarm issues, the overcrowding of the 
brood-nest is largely relieved, both within the swarm and within the 
parent colony. 
Some important swarm-preventive measures, therefore, are: 
(1) Careful selection of stock in breeding. 
(2) The use of brood-chambers large enough during the spring 
brood-rearing period to hold the maximum amount of brood without 
crowding. 
(3) The use of good worker combs in the brood-chamber to prevent 
a reduction of the available brood-rearing space. 
