Co-sleeping is a practice in which babies and young children sleep close to one or both parents, as opposed to in a separate room. Co-sleeping individuals sleep in sensory proximity to one another, where the individual senses the presence of others. This sensory proximity can either be triggered by touch, smell, taste, or noise. Therefore, the individuals can be a few centimeters away or on the other side of the room and still have an effect on the other. It is standard practice in many parts of the world, and is practiced by a significant minority in countries where cribs are also used.