Some bees also use clustering as a form of defense. Japanese honeybees, Apis cerana japonica, can cluster around the predatory hornet, Vespa mandarinia japonica, to kill it. They are able to do this because the temperature within the cluster rises to 48 degrees Celsius which is above the upper lethal limit range of 44-46 degrees for the hornet. This temperature does not aversely affect the honeybees because their upper lethal limit is slightly higher, 48-50 degrees (Schmidt-Nielsen, 1997).
 
 

photo courtesy of James H. Cane, USDA-ARS, www.loganbeelab.usu.edu