Baby rattles are simple toys designed to stimulate infant development through the senses of sight, sound and touch. Most are constructed from wood, plastic, rubber, or fabric and contain small pellets to generate a rattling sound. Manufacturers must be especially aware of potential choking hazards and sharp edges during the design phase, since either could potentially injure a child. Parents usually place rattles near their babies and allow them to naturally interact with the toys.
Rattles are more than simple toys when it comes to child development. A newborn's vision is still underdeveloped for several months, which leads him or her to become more of an auditory learner. When infants encounter baby rattles for the first time, they may not even see the toys clearly. They begin to realize that a world outside of themselves does indeed exist, and they can interact with the rattle through the grasping instinct. Gripping a rattle and creating familiar sounds gives very young infants the first notion of a subject-object world.
Another important stage in a infant's development is cause and effect. Baby rattles are designed to perform consistently, so a child soon learns that there is a direct relationship between his or her actions and the desired results. If an infant were presented with a rattle that didn't make a sound, he or she would become very confused and frustrated. Different toys with different sounds, however, might stimulate a baby's natural sense of curiosity. This idea of different causes and effects leads directly to other early infancy toys, such as mobiles and activity boards.
Many rattles are sold along with teething rings. Babies going through the painful process of teething may use both to soothe their gums. Infants also tend to process information about an object by tasting it, so all toys must be kept as clean as possible. They should also be inspected for cracks and other damage. The materials used for rattling should not be toxic, but accidental ingestion could be a frightening experience.
Commercial baby rattles are generally discarded as the infant develops into a toddler. Toddlers may still enjoy toys that generate noise, but a rattle as such may no longer hold their interest. Some parents or grandparents may create sturdier toys called "heirloom rattles" out of turned wood. These rattles may be stored for future generations or kept as a permanent memento of a child's first year of life.