16 BULLETIN 96, U. S. DEPARTMENT OF AGRICULTURE. 



colony and partially to know their condition, to open the hive under 

 experimentation. The results recorded by the thermometers on all 

 of these occasions are pronounced. In the course of the observations 

 on this colony it was found impossible to disturb the colony in the 

 slightest degree, even to remove and replace a thermometer, to 

 jar the colony, or to puff smoke in at the entrance, without notice- 

 ably affecting the temperature. These effects, as in the case of open- 

 ing the hive, were not always temporary, but sometimes lasted for 

 hours. Any disturbance resulted in an almost immediate rise in the 

 temperature, and was appreciable throughout the cluster. 



On March 12 the colony was opened for 15 minutes at 1 o'clock 

 in the afternoon. The thermometers throughout the hive and even 

 the one below the frames to some extent registered an immediate 

 rise in temperature. When the hive was closed the cluster was soon 

 reestablished but it was several hours before the temperature in the 

 margins of the cluster became normal. On the interior of the cluster, 

 however, the excitement and its effects were not so soon overcome. 

 The curve for c shows that not until the next day did conditions ap- 

 proximate normal ; the effects were appreciable even the day following 

 the opening of the hive. 



These results agree with the experience of many practical bee- 

 keepers, who consider it unadvisable to open their hives during the 

 winter. 



BEHAVIOR OF THE CLUSTER IN WINTER: OBSERVATIONS ON THE CHECK 



COLONY. 



By means of the check colony with glass top and bottom, described 

 on pages 5-6, it was possible to watch the movements of the bees 

 throughout the winter at any time of day or night. 



Various theories have been advanced by beekeepers to account 

 for the behavior of bees in winter, but the writer is not aware that 

 they are based on continuous and close observation. For instance, 

 it has been maintained by some that bees semihibernate; by others 

 it is affirmed that there is at intervals a general warming up of the 

 colony in order that it may feed. The theory is that at stated periods 

 bees generate enough heat to enable them to brave the cold and to 

 expand the cluster sufficiently to enable them to reach fresh stores. 

 It is not necessary to multiply theories on the condition and activities 

 of bees in winter. 



In a previous portion of the text the relation of the temperatures 

 of the cluster to the temperature of the outside air has been suffi- 

 ciently considered. It remains now to describe the activity of the 

 bees as seen in the glass check hive. In some respects the move- 

 ments or the reaction of the bees r and more particularly of the cluster 

 as a whole, to the stimuli of changes in the atmospheric conditions 

 was rather pronounced. 



