Tail-Twining is an affectionate practice of the tiny titi monkeys of the Amazon.
Two, three, or four titis sit on a branch while resting or sleeping and wrap their tails together into a friendly, loving spiral.
Titi monkeys are the New World monkeys of the genus Callicebus. They are tiny creatures and grow to only 18 inches in body length.
They jump easily from branch to branch, preferring dense forests near water, and are also called Springaffen, which means jumping monkeys in German.
One reason why they are usually sitting or sleeping with tails entwined is because grooming and communication is important for the dynamic of the group, being social animals and all.
The Titis monkeys eat mostly fruit and sometimes insects and even bird eggs that they find in the forest.
They are also monogamous, which means they mate for life.