Complex sentence: Leaving the hive, foraging bees collect sugar-rich flower nectar and return to the hive where they use their "honey stomachs" to ingest and regurgitate the nectar repeatedly until it is partially digested.
Split into simpler sentences: Leaving the hive, they collect sugar-rich flower nectar and return. In the hive, the bees use their "honey stomachs" to ingest and regurgitate the nectar a number of times until it is partially digested.