What do parasites found in humans and animals primarily feed on?

Parasites found in humans and animals primarily feed on blood and living matter. This is because most parasites have evolved to depend on their hosts for survival, extracting nutrients that are essential for their growth and reproduction. Blood provides a rich source of nutrients, including proteins, sugars, and other vital compounds, which the parasites utilize to thrive.

While some parasites may interact with skin cells, chemicals in the bloodstream, or even hair and nails, these are not their primary food sources. Instead, blood and other living tissues offer the most direct access to the nutrients they need, allowing them to maintain their lifecycle and reproduce effectively. This relationship exemplifies the nature of parasitism, where one organism benefits at the expense of another.