Gross doesn’t have half-describe it
Looking at these squiggly lines is making us nauseous. The only thing that squiggly and slimy is parasites. What they’re doing on a wooden board is beyond us, but we think the OP should’ve just burned the whole thing. With a flamethrower.
But as it turns out, these aren’t parasites. These weird, squiggly objects are actually eggs of an aquatic fly. We’ve seen cockroach egg pouches, and they don’t look nearly as gross as these things. Even looking at this picture too long is giving us the heebie-jeebies. And we truly apologize that we had to expose your eyes to this super-gross pile of eggs.