Aphids are tiny insects that live on and eat the leaves of plants, removing vital nutrients from the plants.

The close relationship between two different species in an ecosystem

A symbiotic relationship where one species obtains food or benefits from another species without benefitting or harming the other.

A symbiotic relationship that benefits both members of two different species.

A symbiotic relationship where one organism (the parasite) benefits from and hurts another (the host).

Usually the parasite is getting food from the hosts body.

Mockingbirds will push the eggs out of a blue bird's nest and use the nest for it's own babies

A fish will eat the left over food scraps from the shark's meal. The shark is unharmed from the fish.

A plover bird eats parasites off a crocodile’s skin. The crocodile provides the plover protection from predators.

Clownfish live near sea anemones. The anemones provide protection for the clownfish, who are immune to the anemone's stinging tentacles. The clownfish help lure in prey for the anemones.

Barnacles create a home by attaching themselves to the skin of a whale. The barnacle is a filter feeder and obtains food as it rides on the whale. The whale is not affected.

Fleas obtain nutrients by feeding on the blood of a dog.

Oxpecker birds feed on ticks and other insects found on the rhino’s skin. The rhino provides protection for the oxpecker.

Bacteria living in a cow’s stomach help the cow digest cellulose in the grass. The bacteria are protected in the cow’s stomach and are provided with food (cellulose).

Hermit crabs live in shells made and then abandoned by snails. This neither harms nor benefits the snails.

Mistletoe vines wrap around a tree, robbing the tree of water and nutrients.

A leech attaches to the skin of a boy swimming in a lake, and feeds on his blood.