bullfrog tadpole

i just got a bullfrog tadpole from the LFS i work at. it has its two hind legs already. during the morph from tadpole to frog, doesn't it not eat anything but just absorbs the nutrients from the tail? this is what i've read before... is it wrong? also, anyone know a good food for the frog once it's done morphing besides crickets? (can't get crickets around here....)

thanks for any help