I bought some bloodworms a while ago and fed my fish. Its been three months now and there still alive! Is this normal? I thought that they only lived for a few weeks and then turned into insects. What I started observing in my tank too is that they start to poke their bodies out of the gravel and I guess filter the water.... by the hundreds.... My fish aren't even actively eating them? Are these even bloodworms?!! Or have they mutated into superworms? 
