Parents are taught that when a baby rubs their eyes, it's a telltale sign they're ready for a nap. But why do babies rub their eyes when they're tired? What triggers this behavior, and what purpose does it serve?
"Unfortunately, we can't ask a baby exactly why they're rubbing their eyes," Dr. Rebecca Dudovitz, an associate professor of general pediatrics at the UCLA David Geffen School of Medicine, told Live Science.
