What organism is this in my container?

[bugseyjk]

Hello, thanks for reading this. I am volunteering for an Opae Ula shrimp awareness workshop and currently taking care of aquatic snails for the time being. So I do not have much knowledge on aquatic snails.
I have noticed from yesterday that 2 small and dark organism is in my snails container. It was quite agile so I suspect it is not my snails. I have recorded and the link can be found below.
Do you know what this organism is? Thank you very much!

Edit: broken link

 

[richiep]

Can you try a photo

 

[StarGirl]

Hello, thanks for reading this. I am volunteering for an Opae Ula shrimp awareness workshop and currently taking care of aquatic snails for the time being. So I do not have much knowledge on aquatic snails.
I have noticed from yesterday that 2 small and dark organism is in my snails container. It was quite agile so I suspect it is not my snails. I have recorded and the link can be found below.
Do you know what this organism is? Thank you very much!

Edit: broken link

You have to go through a video streaming service first like YouTube and then paste the link here. You can't directly upload videos.