Round buzzing things

This morning, after taking the boys to school, I was outside doing my business. I turned my head and there were these BIG round buzzing things flying from flower to flower! I didn't realize I had parked my behind so close to a bush with nice bright pink flowers. Anyway, I wanted to get a really good sniff but my mum wouldn't let me! They had all this stuff stuck to their legs and they did smell really nice and made such a 'buzzzzz' sound. I bet they would have tasted really good...