Introduction

Earthworms have been known for quite some time as being an integral part of ecosystems across the globe. They play an essential role in cycling nutrients essential to plant species in the soil they inhabit. There are also hundreds of species of animals whose diet consists of earthworms, sometimes almost exclusively (Curry 1998). Today it might seem obvious that earthworms play an important role in ecosystems, but it was Charles Darwin that brought the importance of them to the public (Edwards 1998).

Studies of earthworms have since given us a more complete view of animal behavior, ecology, and the history of the planet. A study conducted on islands, including newly formed volcanic islands has tested the hypothesis that earthworms cannot travel across salt water (James 1998). While we continue to study earthworms, we are continually learning more about their habitat and behavior.

There is much known about the factors affecting the presence of earthworms such as the presence of organic matter, soil texture, and moisture level. Earthworms prefer soils with a medium clay content; while it has been shown that earthworm activity as increased with an increase in moisture (Curry 1998).

This experiment is investigating food preference of the specific earthworm species, red wigglers (Eisenia foetida) in regards to organic matter content. We will use the data collected to determine if there is any preference. Our initial hypothesis is that red wigglers will prefer soil with an organic source over soil lacking an organic source. Also, we investigated a preference of organic material between newspaper and grass. Nitrogen and pH levels were measured to see if they could have an impact on food preference.