Please help! Should I be concerned

[Mr.Guy83]

Sorry for the poor pictures but it’s the best my phone could do because these little guys are so small. Can anyone tell me what these might be? They are on my glass. If they are something bad. How can I get rid of them.
Thanks

 

[T-J]

Looks like pods to me. Good guys. And free fish food!

 

[KJ]

Look like some kind of slugs to me!

 

[Jekyl]

Doesn't look like pods to me. Almost like worms.