This statement appears to be false, since infectious agents don’t move themselves to “look” for a host. Infectious agents (like viruses and bacteria) can be transferred to any living organism they come in contact with. They only infect that individual when the immune system cannot combat an initial infection and the agent spread throughout the body (causing symptoms from the immune systems reaction). So because of this, the statement should be corrected to “Infectious agents move themselves and can successfully infect susceptible hosts”