Views:669 | By: Maureen Viruses are the most common living things. They rely on the cells of other organisms to survive and reproduce, because they can't store energy on themselves.

Viruses are like predators with a specific prey they can recognize and attack. Viruses that do not recognize our cells will be harmless, and others will infect us but will have no consequences for our health. Many animal's and plant's species have their own viruses.

The most important ones to humans are the ones that infect us. Some families of viruses can stay dormant in the body for long periods of time without causing negative effects.

One a person is infected with a virus, their body becomes a reservoir of virus particles, which can be released in bodily fluids such as; by coughing, sneezing or even touching surfaces.

A virus that replicates faster and kills its host very quickly may not have an opportunity to spread to a new host. On the other hand, viruses that replicates slowly and causes little harm, may have plenty of time to spread.