This revealed that coughing, sneezing, yawning, lapping water reminiscent of bath time and the squeaking of toys all activated a part of the brain known to process speech.

You can also pay him back by sending a new toy or taking a bath together with him.

It only takes a minute to look in on the scene, recognize that the child is doing something good like cleaning up the toys, and briefly say that the behavior pleases you.