SneakBetta
Fish Addict
About a week ago I noticed my tank was over-heated. I kept the light off for two days in hopes that it would cool down. Well, it did! But, when I turned the light back on I noticed there were these little worm/bug looking things ALL OVEr the walls of the tank! What are they? They are now all gone but I don't know where they went
What are these and are they bad?

What are these and are they bad?