The Barbary macaques of Ouzoud are famous — or notorious, depending on what they've taken from you. A population of several hundred lives in the cliffs and olive trees around the falls, and the animals have been closely habituated to human presence over decades of tourist traffic. They will approach tables, investigate bags, and make direct eye contact with the practiced confidence of creatures that know they are not going to be chased away.
Watching them is genuinely entertaining. Family groups move through the trees above the café terraces, juveniles play on the rock faces beside the falls, and the adults keep a watchful eye on the food supply. Do not feed them — the signs all say this and the guides will tell you the same, because fed monkeys become aggressive and lose wild behaviour. Do keep your bag closed. The best views of the macaques, without the competition for snacks, are along the quieter paths at the base of the gorge in the early morning before the crowds arrive.