Solitary play: From three to 18 months, babies will spend much of their time playing on their own. During solitary play, children are very busy with play and they may not seem to notice other children sitting or playing nearby. They are exploring their world by watching, grabbing and rattling objects. Solitary play begins in infancy and is common in toddlers. This is because of toddlers’ limited social, cognitive, and physical skills. However, it is important for all age groups to have some time to play by themselves.