From around the fourth month, babies learn to coordinate their new perceptive abilities including vision, touch, and hearing as well as motor skills such as grasping, rolling over, sitting up, and may be even crawling.
In the past, many of the actions undertaken by your newborn would have been based on simple reflex moves, but soon your baby will start touching, feeling, and rubbing the contours of different objects lying around him/her. And this is when his/her interest in toys and games increase.
So far, you may have been littering toys around your baby all the time but he/she would either be unable to concentrate on any one object or simply be uninterested in doing so. But by the fifth month or so, your baby will start interacting with toys in an unprecedented manner.
This is also the time when your baby will have the propensity to taste almost everything. By the age of four months, your baby can easily bring a toy to his/her mouth. He/she will use his/her fingers and thumb in a claw-like grip to pick up objects. Because at this age babies will instinctively explore objects by putting them in their mouths, it is essential to monitor your child at all times.
Development will keep on progressing, and by the age of six to eight months, most babies can even transfer objects from hand to hand, turn them from side to side, and twist them upside down. Babies also discover their feet and toes during this stage. This will lead your baby to interact with toys and play around a great deal more.
Baby-proofing the house hence is of great importance during this time. Make sure there are no small loose objects like needles, pins, batteries, stones, lighters, matchsticks, deodorants or any other such potentially dangerous substance which can threat your baby. Your baby does not know the difference between harmless toys and potentially harmful objects. Also be wary of his/her toys having small parts that your baby may accidentally swallow.