Feeding baby birds

What kind of food would you expect birds to prefer to take back to their young? The reason I ask is that I put out a shallow tray of very soaked meal worms (I prodded them with a stick to make sure they were soft), and a tray with a mix of birdseed and suet pellets. Mr & Mrs Blue Tit (or poss coal tit, I'm not sure now) and Mrs Blackbird all made a bee line for the second tray. I would have thought that soaked mealworms would have been more popular. Any thoughts?