Bee on knapweed

Tried again to do some gardening today but I seem to be easily distracted nowadays.
This time it was the bees fault. Spent ages trying to photograph one on a flower but most were moving too quickly for me. Eventually caught this one on what I think is a knapweed flower. I planted out some wildflowers a couple of years back and last year thought I'd lost most of them but this year I'm starting to see some return including this one. They are well liked by the bees but I was trying to attract some butterflies. perhaps its too early yet.