New bee for me

It's one I've spotted but not one I've been able to photograph.  He's tiny and moves quite erratically. So, I haven't worked out what he is yet but hoping those little white shoulders might help. But, more than that, what is that globule coming out of its mouth?!

The morning, a lovely stroll. A desperately awful bike ride (that's a rare thing to say!), collecting a wheel full of tarmac and stones (I wasn't even on a resurfaced bit!) - at least it was short.  The rest of the afternoon was spent trying to get the tarmac off and refreshing the water system in the van. Mucky! But not any more!