We are all dependent on sleep cues. For example, most of us like to sleep in beds, prefer certain sheets, a night light, reading first, white noise, and pillows (often we have a favorite type of pillow!). While other adults around the world never sleep in a bed or use a pillow.
Babies have sleep cues too. For months before birth, they always sleep with constant soothing rhythms (rocking from the mom’s breathing, snug holding in the belly and rumbly white noise…as loud as a vacuum cleaner!). That’s why it is so odd – and upsetting – for many babies to be deposited in a totally quiet room and flat, still bed after birth.
We use motion all night in SNOO because it helps babies quickly learn better sleep habits (more sleep at night, more awake during the day). However, by 4-6 months most babies are ready to give up the rocking. The SNOO app has a weaning feature which lets parents set the time they want the motion to gradually reduce until the all-night motion eventually stops. This prepares babies for an easy transition to the crib.