Gastrotrichs are bilaterally symmetric, with a transparent body and a flat underside. Many species have a pair of short projections at the rear end. The body is covered with cilia, especially about the mouth and on the lower surface. Its two end projections have cement glands. This is a double-gland system where one gland secretes the glue and another secretes a de-adhesive. Like many microscopic animals, their movement is mainly powered by hydrostatics.