1. Acacia Trees and Ants: This is a classic example of mutualism. The acacia tree provides food (nectar from extrafloral nectaries) and shelter (thorns) to the ants. In return, the ants protect the acacia tree from herbivores and competing plants. They aggressively defend their "territory" from any intruder, even larger animals.

2. Desert Lizards and Thorny Devil Lizards: The thorny devil lizard and some other desert lizards rely on ants for their primary food source. To attract ants, they have a special tongue that can capture them quickly. The lizards don't directly provide anything in return, but their feeding habits help to control the ant population. This is considered a form of facultative mutualism because the relationship is beneficial but not essential for either species to survive.

Let me know if you'd like to explore more examples!