I am having a bit if difficulty feeding my dwarf puffers. I currently have about 8 neons in there with them. I feed them blood worms and mysis frozen shirmp.. 2 out fo the 3 dwarf puffers eat, yet there is one that isnt.. Im afraid soon it will starve like the other 3 i bought.. What seems to be the problem here? Some dwarfs eat while others wont..