This research was conducted in 2008 and 2010 in the experimental apiary of the Warsaw University of Life Sciences. Worker bees were stored in transport cages in their own colonies and stranger colonies. The number of injuries and the death rate were checked twice, after 3 and 7 days of storage. In total, 6720 bees were examined (3360 workers from their own colonies and the same number from stranger colonies). The number of injured and dead workers had an exponential distribution (skewness>1). The worker bees sustained significantly more leg injuries (missing leg segments - 92 - 96%) than injuries of arolia (13 - 15%), wings (1 - 7%) or antennae (1 - 2). Worker bees stored in stranger colonies were injured significantly more frequently than worker bees stored in their own colonies. A significantly greater number of bees died in stranger colonies than in own colonies. The fact that bees stored in own colonies were injured proves that, even if they have the same smell, bees kept in cages provoke aggressive behavior from bees belonging to the banking colony.