An expert in child safety says the key to keeping young children from wandering outside is to get a second door lock and install it up high.

David Drutz, owner of Toronto child safety store Kiddie Proofers, told CBC News that it doesn’t matter how much parents spend on a second lock because any additional lock will provide more protection if it’s out of reach of children.

A three-year-old Toronto girl was found at a grocery store near her house at 2:20 a.m. on Monday. Police said she put on her rain boots, unlocked a door and walked to the store while her parents slept. The store called police. The girl watched cartoons with officers at the police station until her parents picked her up.

Drutz said parents should never underestimate the ability of a child to unlock the doors of a house or push open a window to get outside.

“A primary lock works well, like a deadbolt, a handle. The issue is kids can reach them and they see you using them all the time,” he said. “A little bit more spent will give you a better lock, but any lock, from $2 and up, is better than nothing at all.

“We like to get things out of reach. If children can’t reach them, they can’t unlock them. If they can’t unlock them, they can’t get out.”

To keep a child safe, it’s important to child-proof windows as well as doors, he said.

“It’s summertime, so we’re opening our windows. The only thing protecting the child from actually leaving is the screen.”

As for apartment buildings, Drutz said parents may need to be even more careful.

“Apartment buildings are designed to get out of. For fire purposes, every single door in that building is designed to push at and go out. Don’t assume because I’m on the 14th floor, how is the child going to get out? It happens all the time,” he said.

An extra deadbolt can cost about $25, while an extra chain lock will cost about $10.

Here are three locks that can help parents sleep better at night:

1. Door Guardian Deadbolt A drill is required to install this and it comes with screws. It takes about 15 to 20 minutes to install and retails for $27.95.

2. Door Flip Lock A drill is required to install and it comes with screws. It takes about 10 minutes to install and retails for $7.99.

3. Sliding Window Lock. It’s a peel-and-stick adhesive and retails for $8.99.

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