Babies and toddlers are natural explorers who like to ask questions and make discoveries. That’s why they’re so drawn to doors, because there’s a degree of mystery in what they can’t see. To keep your little wanderers indoors, invest in doorknob covers so they stay inside the safe perimeter of your home.

Doorknob covers are simple plastic devices that snap onto knobs. They’re relatively simple for adults to maneuver, but for babies and toddlers they’re an obstacle that prevents them from opening a door. Because of their height and the tiny size of their hands, toddlers find it extremely difficult to get the necessary grip to open the door. Even if they try, an adult soon becomes aware of what they’re doing and can redirect the child’s attention to a safer activity.

If you’re ready to add another layer of child safety and protection to your home, we invite you to read this buying guide. We cover the features and benefits of doorknob covers so you can choose the right set to install in your home. Take a look at some of our favorites, too.

Doorknob covers are essential for parents with young children. Even under the watchful eye of an adult, and the use of baby gates, some children can reach doors and open them. Doorknob covers are an obstacle that can provide enough time for an adult to reach a child before they go out the door.

Some families who care for relatives with cognitive disabilities also purchase doorknob covers. The devices aid in securing the home’s perimeter so their family members can’t exit the home unattended.

Doorknob covers make it hard to twist the doorknob without a concerted effort. Toddlers who are shorter than the height of the doorknob can’t see or reach the part of the doorknob that needs to be manipulated to open the door. Covers are also designed for adult hands, so even if children can reach the doorknob, their hands aren’t big enough to open the door.

• Installation: The process is simple; you can install doorknob covers in an entire home in less than 20 minutes. For most models, you just snap the opposing pieces together over the knob. If the cover has a shutter that protects the lock, make sure you open and close it a couple times to loosen it up for easy key or lock access in the future.

• Removal: As expected, it takes some effort to remove a doorknob cover. While you can press and pull the plastic pieces apart, it might be better to use a flathead screwdriver as a lever to pop them open. You might break the cover using this method, so have replacements on hand just in case.

Most doorknob covers are white. There are some models available to match doorknobs so they’re less of an eyesore, but you can expect to pay a premium for these. There are covers in brushed silver, gold, copper, brass, white, and gray. It’s more common to find colored covers for round doorknobs as opposed to knobs of other shapes and styles.

Most doorknob covers are made of hard plastic that resembles the plastic used in strollers and children’s toys. Some models are made with BPA-free and nontoxic plastic, which is definitely a selling point for some parents. There are also models that have undergone and passed elective safety testing. The plastic might be approved as food grade or be particularly strong to hold up against breakage. Some covers made of recycled materials have earned eco-friendly status.

Doorknob covers are intended to be an obstacle for children, not adults. As a result, some covers are equipped with a quick-release feature so the average person can open and close doors easily. This can be as simple as small holes for the thumb and fingers to connect to the knob. In more advanced styles, there is a lateral squeeze mechanism that enables you to grip the knob.

Some doorknob covers are designed to also protect a lock or keyhole that is also part of the knob. These models feature a little shutter that opens or closes to expose the lock or keyhole. In some cases, this shutter gets a lot of wear and tear, so it could break off, requiring you to replace the cover.

Doorknob covers range in price from $3 to $30.

Inexpensive: At the low end of the price range, between $3 and $8, you’ll find packs of two covers.

Mid-range: Many covers priced between $8 and $15 come in packs of four and sometimes include a quick-release feature.

Expensive: At the high end of the range, between $15 and $30, are doorknob covers made with nontoxic materials. These come in packs of four or six and are sometimes packaged with other child-safety accessories.

• Clean doorknob covers regularly. Because lots of hands come into contact with doorknob covers, it’s important to wipe them down on a regular basis.

• Add doorknob covers to a baby registry. In addition to your other child and baby safety items, remember to add doorknob covers, too.

• Install doorknob covers on both sides of the door. For maximum safety, install doorknob covers on both knobs of each door.

• Educate babysitters on lock safety. Communicate the importance of child safety to your babysitters, and show them how to operate and resecure each doorknob cover and child-safety lock after each use.

In addition to the products in our matrix, we like the UnaBaby Safety Covers. These hard plastic covers come in four colors to blend in with your round doorknobs. They’re easy to install and have a quick-release gap for adults to use. They’ll hold up to years of use, until all your little ones reach a safe, independent age. The manufacturer offers a 100% lifetime guarantee, and consumers confirm it stands behind its products. For an extra layer of security, we like the Betertek Lockable Safety Cover. Installation is easy, and it has locking components to make sure it stays closed even when pulled on by children. There’s also a lockable front window that covers the lock, making accidental opening a thing of the past. This odorless, nontoxic plastic doorknob cover offers a universal fit because it’s compatible with slightly larger round knobs.

Q. My children don’t need doorknob covers anymore, so what do we do with ours now?

A. You might want to keep them in the house for when younger children come to visit. Another option is to share them with another parent with young children. You could also save them with some other baby items you put aside for sentimental reasons, just in case you welcome another bundle of joy in the future.

Q. I have a baby gate. Isn’t that enough protection from doors?

A. While baby gates make excellent perimeters, some children can knock them down or climb over them. After your children reach a certain height, baby gates are too short to be effective. That’s why doorknob covers are ideal, because they’re a simple yet effective extra layer of protection to keep your little ones indoors at all times.

Q. How many doorknob covers should I get for my home?

A. It’s recommended that you get at least four, which is why they’re generally packed in sets. Get as many as you need to cover the knobs on doors that go outside, as well as doors that go into pantries and closets. Some children view these small alcoves as hiding places, yet they could get stuck or injured inside.

Q. My dog chewed on the doorknob cover, so can I still use it? It hasn’t fallen apart and just has teeth marks.

A. It’s not unusual for dogs to confuse doorknob covers with chew toys. You’ll need to communicate to your dog that chewing isn’t allowed on the cover. As far as the cover goes, it’s probably a good idea to replace it, because the chewing may have warped the plastic, which could affect the security of the mechanism.