Pest or just ugly?

[dotsfriend]

While doing a water change this morning, I found a bunch of white "maggot-like" things all over in my sump. They are mainly on the baffles but also on the glass. I don't see anything in the display tank (yet). I've been watching these things for an hour or so and they do not appear to move. Some are quite small (maggot-sized) while others (like the one pictured) is about the size of my pinky fingernail. Thoughts on what these things are and how or should I get rid of them?