Earthworms are digestion machines that consume the bacteria off of decomposing organic matter. An earthworm's body is divided into segments and when it is damaged or cut, it can partially regenerate these segments. The amount of regeneration depends on the health of the earthworm, the species and the segment where it received the damage. For example, an earthworm has an easier time regenerating its tail than its head.
To experiment on an earthworm using an electromagnetic field, a scientist needs a means of generating electricity; this could be as simple as a battery or as complex as a cell that emits a high voltage of electricity. An electromagnetic field is generated by sending an electrical current into the earthworm's environment, which consists of soil inside a holding container. The current is left running over a specific period of time, anywhere from one hour to three days or more, depending on the goal of the experiment.
An electromagnetic field may have an effect on the rate and amount an earthworm is able to regenerate. Scientists theorize that the field stimulates the reproduction of cells by literally charging them up. However, as of 2011, research on increased regeneration due to an electromagnetic field is limited. Through this work with earthworms, scientists hope to find a key to cell regeneration in the human body through therapeutic use of an electromagnetic field.
In a 2009 study performed by a team at the University of Zagreb in Croatia, scientists experimented with the effect of radio frequency electromagnetic fields on earthworms. The results of this study revealed that exposure to the electromagnetic fields caused an increase in the production of 13 different proteins and a decrease in the production of six proteins. This change in protein production suggests that exposure to radio frequency electromagnetic fields, with which humans frequently come into contact, has an effect on the biochemistry of living organisms.