They can have feelings of discomfort, exhaustion, hunger, loneliness, boredom, anger, pain and general unrest. But one of the main reasons is popping ear. According to The Health Journal, the most common reason for their discomfort on flights is because cabin pressure presses down on their sensitive ears.

The primary cause for babies crying during a flight is intense ear pain caused by rapid changes in air pressure, especially during the descent. Because a baby's Eustachian tubes are significantly narrower and more horizontal than an adult's, they cannot equalize pressure as easily. As the plane descends and cabin pressure increases, it pushes on the eardrum; if the tube doesn't "pop" to equalize it, the result is sharp, localized pain. Other factors in 2026 include the dry, recirculated air which can cause nasal congestion (further blocking the ears), the unfamiliar loud engine hum, and general overstimulation from the bright lights and crowded environment. A high-value safety move for parents is to breastfeed, bottle-feed, or offer a pacifier during takeoff and landing, as the swallowing motion helps open the Eustachian tubes and naturally "pops" the baby's ears.