The annelid worm Lumbriculus variegatus has been used to study the effects of environmental toxins, especially in sediments, as the worms generally live partially embedded in stream bottoms. They are easy to culture in water. The worms display several characteristics that can be measured, including escape responses triggered by touching and regeneration after fission. They naturally reproduce by asexual fission, but can also regenerate the missing end and become a complete worm if halved by amputation. Scientist partner, Dr. Judith Roe from University of Maine at Presque Isle has developed two assays, one to test effects of toxins on behavior and the other to test effects of toxins on regeneration. Annelid worms can easily be reared in the classroom and students can learn to handle the worms and distinguish the head and tail ends of the animals for analysis of behavior and regeneration.