Short description
Parasites are organisms existing in or on another living thing from which they obtain nutrients and which they cause harm.

Detailed description

Parasites include animals, plants, fungi or bacteria. They are detrimental to their hosts as they obtain their energy from them but also because they may release toxins and harm the host mechanically by damaging skin and tissue. Examples for parasitic organisms are lice, tapeworms and the malaria pathogen Plasmodium.