Tiny shells and bugs on glass

[aiber]

I noticed many little bugs "walking" around on the glass. Also, many little shells. What are they? Info is appreciated

 

[bang guy]

How small are the shells?
Can you describe the bugs better. I'm sure they are beneficial but I need a better description if you want to know what they are.

 

[bigarn]

Could these little shells possibly be baby snails?

 

[aiber]

I would have to take a picture....
Thanks for the info