Well they can't eat them, but they can pick them to death.. and I don't think Thats a cool thing to let happen.
If you want fish they can eat buy a few pregnant feeder guppies plus some more males and females, the babies should be the right size for them.
Oh, and most people at pet shops have no clue what they are talking about, if you have questions, you'd do alot better to ask here or another good fish site
How about acually feeding them fish food? sorry I think feeding fish live foods is mean. I may be the onyl one who thinks this, but if your fish are small, why not feed them fish food ?
come to think of it my dad made me get some white labs, I got really mad though saying he shouldn't get things for my tank unless I ask...Plus i had no info on them but they are pretty mucj just a whight lab same as the yellows. Oh well the last fish that will complete the stock will be a Zaire or mibimwe frontosa. Sorry for my ramblings just thought it might help. I'll post a pic later.