What are some examples of mutilism?

Answer 1

A hippo and a bird; the bird cleans out the hippo's teth and having a meal and the hippo is beinged clean. or

A bird and a army of ants, the bird follows the ants (without eating the ants) but the ants stir up different insects and the bird eats the insects. or A squirrel and tree, the squirrel gets shelter, a place to store nuts (squirrels only usually fine 10-18% of the nuts that they bury) and the tree scatters the seeds of the squirrels while the tree remains unharmed but no greater than before.