Hermaphroditic, planaria may reproduce asexually by regeneration or by exchanging sexual gametes with another worm. Scientific evidence suggests if reproduction is asexual, then certain conditioned responses can be passed on to offspring. For instance, although they possess primitive central nervous systems, planaria are able to learn to travel through a maze to eat or react to other simple stimuli. After regeneration, these learned actions are remembered by the parent planaria, but are also adopted by the newly formed turbellarian.