What is an example of an external parasite?

Ticks are classified as external parasites because they live on the outside of their host's body and feed on the host's blood. This feeding behavior is characteristic of external parasites, which rely on their hosts for nutrients while causing potential harm in the process. Ticks attach themselves to the skin of mammals, birds, and sometimes reptiles, thriving in environments where they can easily access hosts.

In addition to harming their hosts directly through feeding, ticks can also transmit diseases such as Lyme disease and Rocky Mountain spotted fever, increasing their impact as external parasites.

In contrast, other examples provided, like worms and flukes, are typically internal parasites, living inside the host's body and often inhabiting the digestive tract or other internal organs. Bacteria, while they can be pathogenic and act as parasites, are microscopic organisms and do not fit the traditional classification as parasites in the same way that ticks do. Their nature does not involve a direct parasitic relationship characterized by external feeding.