The baby was sleeping across his parents' laps. Babies can sleep anywhere as long as they are in the arms of their parents.
I took the above photo while holding on to the overhead handrail while the bus was moving. So the photo is very blurred. I just wanted you to see the smiling faces inspite of the extremely crowded bus.....I have found that most Mexicans are extremely patient and polite to each other. They tolerate hardships with grace.