Hi Branch,
Do you know what they were feeding them before you brought them? They might be wanting their old foods and not the bloodworms.. Just a thought..
If you like you can always try soaking their foods in garlic guard by seachem or the same thing in another brand, the garlic helps with fussy eaters in most cases..
Are they freeze dried bloodworms? Or live or frozen? Perhaps try some freeze dried black worm cubes, stick them to the glass so they can peck at them..