From 2speccers2tools wiki

With the success of more derived Semavermis, more dead matter has begun building up, though the soil is still not developed, so it coats the surface, which a basal lineage has taken advantage of. The Semaworm are the smallest member of their lineage, though makes up for this by being extremely common and reproduce quickly, and are commonly broken up while burrowing through the ground, resulting in more colonies forming. They use the same acid they use to dig through the ground to decompose dead matter, so that they may ingest it, and are most common in areas with lots of life. They store spite they get from food within their cell as a defense mechanism, and are thus immune to it themselves.