Short answer
A predator catches and consumes prey, usually killing it in a feeding event. A parasite lives in or on a host and draws resources over time, generally harming it without immediately consuming the entire host. Both are exploitative interactions, but they differ in duration and what happens to the other organism. 1 2
Both gain resources from another organism; a predator generally consumes prey in an encounter, while a parasite uses a host over a longer association.
On this page
At a glance
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| Question | Predator | Parasite |
|---|---|---|
| Other organism | Prey | Host |
| Typical contact | Short encounter | Sustained association |
| Typical immediate outcome | Prey killed and eaten | Host remains alive initially |
The table summarizes the cited definitions and the article’s stated scope. 1 2
What each thing is
Predator. An organism that captures and consumes another organism, its prey. 1
Parasite. An organism living in or on a host and obtaining resources from it, usually harming the host. 2
Key differences
Ecologists classify interactions by their mechanism, not whether one organism is “bad.” Predators often consume many prey; parasites often depend on one or more hosts during a life stage. Host death can occur later from parasitic disease. 1 2
How to tell them apart
Watch the feeding pattern. A hawk catching a mouse is predation; a tick feeding on a deer is parasitism. Ask whether the consumer lives on or within the same host while extracting resources. 1 2
Where they overlap
Both can regulate populations and drive defenses in the organisms they exploit. Some relationships, such as parasitoid insects, lie between the familiar categories. 1 2
Edge cases
A parasitoid develops in or on one host and ultimately kills it. A predatory plant or microbe can blur everyday assumptions based on animal examples. 1 2
Why the distinction exists
The distinction helps explain food webs, population dynamics and evolutionary responses to different kinds of consumers. 1 2
Common misconceptions
A parasite does not have to be microscopic, and a predator does not have to be large. 1 2
Examples
A wolf eats an elk as prey. A tapeworm absorbs nutrients while living within a mammal host. 1 2
Sources
Sources checked October 3, 2026.
- OpenStax — Community Ecology. Predation; Symbiosis; Mutualism; Parasitism.
- CDC — Parasitic Glossary. Parasite.