When the Lord displayed His activities just suitable for childhood, He was visible only to the residents of Vṛndāvana. Sometimes He would cry and sometimes laugh, just like a child, and while so doing He would appear like a lion cub.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
कौमारीं दर्शयंश्चेष्टां प्रेक्षणीयां व्रजौकसाम् । रुदन्निव हसन्मुग्द्धबालसिंहावलोकनः
kaumārīṃ darśayaṃśceṣṭāṃ prekṣaṇīyāṃ vrajaukasām | rudanniva hasanmugddhabālasiṃhāvalokanaḥ
SB 3.2.28