Bees Flying in the Rain

It has been raining lightly for 2 days now and I didn't expect to see any activity around the hive.  I always thought that bees couldn't fly when it rains but it turns out that if it is not raining too much, the bees are able to  get out and leave the hive. I did see one worker arrive with pollen but the rest were returning with nothing visible. I'm not sure what the bees were doing out there or why they thought it OK to risk being pelted by a deadly rain drop. I love this video as it shows the bees sucking up water with their tongues. [youtube=http://www.youtube.com/watch?v=GMrmbif-KpI]