Australian desert
Parasites
There are many host parasite relationships in the Outback like small hummingbirds and cacti when usually the cactus spikes and spines hurt other animals, but rather than getting hurt the hummingbird jumps around them to find their food. Another parasitic relationship is termites and a tree. When a tree is dying and cant sustain itself the termites decompose of it getting a meal and killing the tree so it doesn't have to suffer.