Hawaiian Honey Bees In Heather?

I was visiting a property the other day and when I walked by this pretty plant with purple flowers in the front yard, the most incredible "humming" could be heard? I looked closer and it was ALIVE with bees! It was almost like they were swarming. I could not have laid my open hand on the bush with out covering at least 3 bees! And they were so wrapped up in the flowers that they completely ignored my presence, so I could get nice and close.

I have no idea what the plant is, hence the title, does anyone know? Very pretty, compact, low growing bush with no thorns. And I really could not catch any scent of note either.