Bumble bees feeding

[BILL.HEARD]

Yesterday I had been tying up some roses and had a number of thorn pricks on my hands, before going in-side to wash up I leaned over some trellis to watch bees working cultivated blackberries in bloom.
After a minute or two a couple of small bumbles landed on my hands and started to feed on the blood coming from the scratches. What nutrition do you think they were obtaining, water from the plasma or perhaps some salts?

 

[jenkinsbrynmair]

Not salts I would think, whilst stopping off to unwind with my cousin in Johannesburg before returning home from Lesotho she took me to a friend's for a braai, their daughter had done a study on whether bees would forage for salt as part of her Master's, the answer was no

 

[HM Honey]

Transylvanian Bumble Bees ????