fry food!

I second Cathy's post. Petsmart sells frozen baby brine shrimp.

My guppy fry are a bunch of spoiled rotten brats and ignore the frozen bbs for a while, but once they realize that's all that's going to fall 'from the heavens', they take them. But I fully agree with you, if the bbs move, they're all over them like they're hot cakes :)
 
Also jellied brine shrimp will do the trick. If they are really young use an infusoria starter if you can (liquifry does this to some extent). If all else fails, put a really strong light on it and grow the algae. They will eat it off the side of the tank.
 
oooh... also try boiling an egg putting the whole thing (or just the yolk) in a blender with a little water and creating a paste/liquidfood (depending on how much water you add) you can feed to them. Usually they love it.
 
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