I was cleaning out my closet and found some old bits of PVC piping that I'd forgotten about. I wanted to find something to do with it and thought of fish of course lol. I was wondering if maybe shrimp could use it? (because the pipes are quite small/narrow)

I was thinking I could partly bury it under the gravel. I'm not sure if shrimp would even use something like that though?

Yup your shrimp will definitely appreciate these! You can bury them under gravel or I've also heard of people attaching plants such as moss to the pipes to make them more attractive or hide them completely.