wtf is in my shrimp tank

never thought i'd have to make one of these posts. these have been on the front of my 3gal for a couple days and i thought they were just stringy algae. when i looked today i realized they're MOVING. as far as i can tell they're only in this area, where theres some algae or diatoms on the plastic (it's a cheap tank from walmart). are these going to harm my shrimp?