Based on the current biological characteristics of life, computer viruses are not living. Computer viruses do have different levels of internal organization. They grow, reproduce, and respond to their environment. However, computer viruses are not composed of cells. Cellular composition is a basic requirement for biological life forms. In addition, computer viruses do not consume organic matter nor do they create thier own organic matter through a process such as photosynthesis. Computer viruses are a phenomenon that encourage us to examine the inherent limitations of the biological definition of life. They encourage us to ask the question of what non-biological life forms might look like.