Mosquitoes can be deterred by using natural repellents that are derived from plants and other natural materials. Here are some natural mosquito repellents that have been shown to be effective:

1. Lemon eucalyptus oil: This oil has been used since the 1940s and is one of the more well-known natural repellents. The Centers for Disease Control and Prevention (CDC) have approved eucalyptus oil as an effective ingredient in mosquito repellent. A DIY mixture can be created with 1 part lemon eucalyptus oil to 10 parts sunflower oil or witch hazel.

2. Geraniol: This natural chemical is found in citronella, lemongrass, and rose oil. Studies have shown that repellents containing geraniol can help keep mosquitoes at bay for a short while, but they don’t work as long or as well as other types of repellents.

3. Catnip oil: This insect repellent is derived from the nepeta cataria plant. It may offer mosquito protection for 7 hours, according to the EPA.

4. Cinnamon oil: This has been shown to help make you a bit less attractive to mosquitoes for up to an hour and a half, which is longer than many other natural oil repellants.

5. IR3535: This is an active ingredient in some insect repellents and is considered "natural" because it is structurally related to a naturally occurring chemical. It may offer up to 2 hours of mosquito protection.

6. Peppermint oil: This oil acts as a strong Aedes aegypti mosquito repellent for 30 minutes, after which it continues to repel them, but not as significantly.

7. Rosemary: This plant contains a natural ingredient that is often a natural ingredient within commercial insect repellents. However, findings suggest that rosemary oil does not provide significant protection against Aedes aegypti mosquito bites or repel these insects.

8. Garlic: The scent of garlic may reduce mosquito attraction to human odor. Garlic oil is a strong mosquito repellent for the initial 30 minutes after application, but the effect weakens after this time.

9. Lemon balm: The strong lemon scent of this plant contains high levels of the bug-repelling compound. It can be grown in containers to prevent it from becoming an invasive species.

It is important to note that natural repellents may cause irritation if you have sensitive skin. When traveling to an area with a high risk of mosquito-borne diseases, the CDC recommends using repellents that are registered with the EPA. Most of those EPA-approved products are synthetic.