Blood worms, Mysis shrimp, small sinking pellets might all be successful. I have never had salamander babies reject blood worms as a first food. I like to use bloodworms as a first food since they all seem to recognize it as food. Pellets might take a little bit of training but as soon as they learn that it is tasty and edible, pellets are all you will need. Small insects and worms are also a good diet. In all honesty, I treat my amphibians almost exactly as I would care for my fish. All of my aquatics eat pellets with worms and shrimp as a supplement. At the right size, cherry or ghost shrimp are an entertaining way to keep them active and hunting