While they don't write love letters, there’s no doubt animals form deep and enduring friendships and use many different ways to form and sustain these close relationships.

Friends are not just a human phenomenon. The benefits of social connections — friendships — are plentiful in many different types of animals. Members of many animal species participate in friendships, ...

Have you ever wondered why pets trust and approach some humans instantly while actively avoid others, the answer is complex and based on internal processing of the pet rather than any external act.