I was blissfully asleep on the couch while my little one was occupied elsewhere with toys, books and my partner. She got bored with what they were doing, escaped from his watch and, sensing my absence, set about looking for me. Finding me on the couch, nose-level, she peeled back my one available eyelid, singing, Mama? Mama?… You there? Wake UP!”

Sound familiar? Nothing limits sleep more than parenthood. And nothing is more sought after as a parent than a nap, if not a good night’s rest.

But Mother Nature practically guarantees the fact that you’re likely to be woken up by a toddler. They’re hardwired to find you (and get your attention) when you’re “away.”

According to attachment theory, when you respond to the needs of your child, a strong bond is formed and woven into their personality, serving as a basis for all future emotional ties. It guarantees that your kids love and come to depend on you. Which means they can feel anxious when involuntarily separated from you, like when you are asleep.

Child psychologist Esther Cohen suggests that it is fairly universal that infants and toddlers try to open the eyes of their sleeping parents. Her theory is that when you are present, but with your eyes shut, you are not responsive, and on some level this causes your child a form of “emotional distress.” So the best and easiest way for them to feel better is to wake you up.

Cohen believes that reestablishing eye contact bridges the gap between your physical presence and your emotional presence, making the situation feel normal again. Your kids are relieved that you are alert and there to interact with them— and that you are available to protect them.

Kids are hardwired to seek our attention all the time

At birth, an infant’s brain is only about 25% of its adult volume. Born particularly vulnerable, babies depend on years of loving care. This prolonged helplessness has resulted in the evolution of certain behaviors—like baby coos, smiles and crying—that increase their odds of survival within the family.

By the time that tiny baby becomes a toddler, they’ve developed a sense of who they are and what they can do in relation to people and things. They also now fundamentally know that they are a separate person from their parents. Toddlers also have a sense of what’s called object permanence—the ability to understand who or what is—or is not—present. That means they can search for objects and people. (And wake them up when they find them. )

It’s a universal phenomenon

When you sneak off for a nap and your toddler comes looking for you, know that this is a natural instinct at play, one they will eventually grow out of. But for now, when you are asleep, to them, you’re not there, so your kids must. wake. you. up.

And for an extra fun fact: Research indicates that this also could be why it’s so hard for you to ignore your partner when working from home. They’re present, but technically not available, so you continually find reasons to interact with them—just like waking them up from a nap.

A version of this story was originally published on Aug. 23, 2021. It has been updated.