A bumblebee nest differs in size and structure from that of a honeybee. Bumblebee nests are smaller and contain far fewer individuals which is mostly due to differences in the method of colony reproduction. Honeybee colonies can contain up to 50,000 individuals, whereas bumblebee colonies usually only contain a few hundred. This means the number of bees available for foraging is low and resources must be allocated accordingly. Assessing the level of food stores is not seen in honeybees, likely because the large colonies make such assessment inefficient. Bumblebees only store enough honey for a few days. By monitoring the levels of the honey pots a bumblebee colony can either up or down regulate the number of bees out foraging. Lab experiments by Anna Dornhaus and Lars Chittka in 2005 showed evidence of this up or down regulation by monitoring the activity level of the hive after the addition of nectar to the honey pots. Hive activity increased when high quality nectar was injected into the honey pots, provided the wells werent already full. When the honey pots were full, there was no significant change in activity regardless of whether the nectar imported was from a high or low quality source. They hypothesized that either the foraging bee does not signal the nest or the nest bees ignore the signal because the demand for food is low. The tropical bumblebee Bombus transversalis' has also been shown to respond to honey pot levels in a similar way.