Looks for objects that are hidden

What is this milestone?

Understands objects exist even when hidden

Object permanence is the cognitive understanding that objects (and people) continue to exist even when they cannot be seen, heard, or felt. If you hide a toy under a blanket, they will actively search for it.

Why it matters

This is a profound shift in how your baby perceives reality. It’s the foundation for memory, abstract thinking, and problem-solving. It also explains why separation anxiety often begins around this time, as they know you exist when you leave the room.

What to expect leading up to it

Before grasping this concept, if a toy is hidden, a baby will simply lose interest as if it vanished. As this skill develops, you'll notice them staring at the spot where an object disappeared or trying to move an obstacle to find it.

How to encourage and support it

Play plenty of peek-a-boo! You can also hide a favorite toy partially under a towel, encouraging them to pull it away. Gradually make the hiding spots slightly more challenging to gently stretch their newfound cognitive abilities.

When to talk to your doctor

The CDC's milestone checklists say what most children (75% or more) can do by each age. They list “Looks for objects when dropped out of sight (like his spoon or toy)” by 9 months and “Looks for things he sees you hide, like a toy under a blanket” by 1 year. If your child is not doing these by those ages, the CDC's advice is not to wait: talk with your child's doctor, share your concerns, and ask about developmental screening. The same goes at any age if your child loses a skill they once had, or if anything else about their development worries you. Source: the CDC's “Learn the Signs. Act Early.” milestone checklists, checked October 5, 2026.

CDC: Milestones by 9 months · CDC: Milestones by 1 year · CDC: all milestone checklists