Hobbies And Interests
Teaching Earthworms
Create a 6-inch, T-shaped maze with 3-inch high walls. Place a small cardboard box at the end of the right hand arm of the T. This becomes the shelter that the worm instinctively seeks. Place the worm at the bottom the the T and time how long it takes the animal to get to the shelter. It may take several tries before the worm understands. After the worm learns to turn right, switch the shelter to the left-hand side of the maze. Test the worm to see how long it takes the worm to figure out where the shelter has gone. Try different types of stimuli to entice the worm to the correct side of the maze. Flood one side of the maze with light, while the other side is shaded. Leave a trail of sugar, salt or crumbled earth. After they have been trained, place two or three worms at the base of the T together and have a worm race to the shelter.
Conditioning Planaria
Planaria are tiny flatworms that live in freshwater. Like earthworms, they can learn to follow a simple maze. Because planaria are swimmers, it is easier for them to maneuver in a Y-shaped maze than turn the corner in a T-shaped maze. Cut a 4-inch trough in a Styrofoam block in the shape of a Y that is 1/2-inch wide and deep. Fill the trough with water from the planaria's tank. Place a planarian at the base of the Y. To train the worm to turn to the right, fill a syringe with air. Give the planarian a puff of air when it starts down the left hand path. These little puffs of air are uncomfortable to the water-loving creatures, but will cause no damage to the tiny creature.
Operant Conditioning
Place a planarian in the base of the Y-shaped maze filled with water. When the worm starts to head down the wrong section of the maze, give the worm a puff of air and flash a bright light at the same time. After several trials, stop puffing the air and simply use the light to direct the worm. The worm becomes so conditioned to experiencing the light and puff together, that it will quickly learn to avoid the bright light.
Cannibal Worms
Planaria have regenerative properties due to the high level of stem cells. An entire planarian can grow from a single portion of the original worm and even pass on what it has learned to its offspring and other worms. After training a worm to go to one side of the maze every time, cut it up. Allow part of the worm to regenerate. Feed several other pieces to worms that have never gone through the maze at all. The regenerated worm will go through the maze just as fast as the original worm. But, the worms that ate the trained worm, even though they had never seen the maze, will also go trough the maze just as fast as the original worm.