A species of sponge producing chemicals that kill the symbiotic algae of a coral growing next to the sponge.

A bee taking nectar from a flower and, in the process, pollinates the flower.

A cuckoo laying her egg in the nest of another species of bird, the reed warbler. The reed warbler is then left to raise the cuckoo chick.

A Rafflesia plant using a specialised absorptive organ, known as a haustorium, to draw nutrients from other plants.