How to make the baby laugh?

It's only a matter of time before the baby laughs. My baby laughs every two months. At first, he laughed and screamed, then he laughed. The baby smiles according to different situations. My baby usually laughs: I sing; I dance; Grandma squatted on the ground to pick vegetables; Cover her face with a cloth and take it away. Don't worry, every baby starts laughing at a different time. My baby can only laugh until now.