How to Naturally Kill and Prevent Fleas

Rachel, from The Essential Girl, is back to share her expertise on essential oils.

Fleas. When your cat gets them, getting rid of them without fogging your house with toxic chemicals can seem nearly impossible!

How to Naturally Kill and Prevent Fleas

And I must admit, I am guilty of taking the fast and easy way out; however, there are a few ways to naturally kill and prevent fleas that don’t require too much extra work and are much safer for you than any commercial flea fog bomb.

Essential Oils and Herbs that Repel Fleas

The first natural remedy I look to is almost always herbs or essential oils (which are just concentrated versions of the herb).

Before I continue, please take note that several essential oils are quite toxic to cats so while you may have read that a certain oil is toxic to fleas, it may also poison your cat.

Here’s a list of essential oils and herbs that are both safe for cats and have flea repellent or insecticidal qualities:

  • Catnip [1]
  • Cedarwood [2]
  • Rosemary


Catnip is a great option for all around natural insect repellent for your cat, and it is conveniently already present in a wide variety of cat products.  On the flip side, it’s rather difficult to find as an essential oil.

Consider sprinkling catnip on your cat’s bedding or carpeted cat tree after it has been washed or vacuumed to remove flea eggs and larva that may be hiding in the fibers.


Cedarwood oil has been tested against fleas in a lab environment and found to be lethal to adult fleas. It is readily available from several reliable suppliers, making it a good option for concentrated flea control.

After bathing your cat to drown any existing fleas, consider adding a drop or two of cedarwood oil to their collar to prevent reinfestation. Cedarwood oil could also be used as a spray for fabrics to kill any fleas as they hatch. I would recommend mixing equal parts water and vinegar in a glass spray bottle (other materials can interact adversely with the oils) and adding 10 drops of oil per cup of liquid. Just be certain to test the spray to make sure it doesn’t discolor your furniture.


Rosemary baths are widely recommended for flea control, although I wasn’t able to find any research on the subject. Most people recommend that you brew a rosemary tea by boiling fresh rosemary in water on the stove, then pouring the (cooled) tea over your pet and letting it dry without rinsing.

If rosemary is indeed effective against fleas, you might consider using it alongside the cedarwood oil on the collar and in the spray.

Related: Rosemary Oil – Just the Facts

Note: NEVER apply an essential oil directly to your cat. Even if an oil is safe for cats, cats tend to be very sensitive to essential oils and are likely to have a reaction.

Other Natural Flea Remedies

Aside from essential oils, there are several other cat-safe flea control methods you can try:

  • Borax (good for carpets, avoid breathing directly, never apply to your cat, vacuum well)
  • Diatomaceous Earth (also good for carpets, avoid breathing, never apply to your cat, vacuum well)
  • Table Salt (usually used in conjunction with borax or diatomaceous earth)
  • Vacuum everything, and often to prevent and control fleas. Even your cat if they will let you. Dispose of everything in an outdoor trashcan immediately to prevent reinfestation.

Keep in mind that it can be difficult to completely eradicate fleas, but through the combined use of these methods you should be able to kill existing fleas and continue to prevent new fleas from flourishing.

Want to learn more about using essential oils with your cat? Take my free essential oils for pets email course! Inside I cover why using essential oils with your pets can be so beneficial, common mistakes people make when using essential oils with their pets, and I answer all of YOUR burning questions! Just click below to get started.

Do you know of any other ways to naturally kill and prevent fleas that I missed, or stories of successes? I’d love to hear from you in the comments!

About Rachel:

The-Essential-Girl-Profile-PhotoRachel is a blogger and bioengineering masters student who lives in Clemson, SC (go tigers!). Her two passions are health and science, and she blends them masterfully in her blog The Essential Girl, where she writes about the science behind essential oils and sorts through the hearsay about clean living.

When she’s not blogging or sciencing the shit out of something in the lab, she likes to drink tea, nom on popcorn, and binge Netflix with her soon-to-be astrophysicist boyfriend.



  1. Amelia
    August 31, 2017 / 4:20 am

    Hello! Your information is very useful. Thank you! However, I’m am worried about my cats health. I have been using lavender essential oils in my diffuser for a few months to help me relax. Also, I found that my cats have fleas a week ago and have been trying to rid them of the little pest without harmful chemicals. I read on another site that lavender kills fleas effectively. I used 4 or 5 drops in a bath of about 5 gallons for my cats. I then dried them thoroughly with a towel and brushed thier fur. Should I be worried enough to take them to the vet? I don’t want to incur expensive fees if they will be okay with discontinued use.

    Thanks in advance for your help!

  2. Alex
    August 1, 2017 / 9:04 pm

    Would i be able to use rosemary/sandalwood in an oil diffuser? How effective would that be?

  3. Rachel
    July 24, 2017 / 7:43 am

    Hi im panicking i just discovered my cat has fleas . My only resource to aid the situation was rosemary oil which i diluted about 10-15 drops into a spray bottle not quite one pint and then all i did was squirt some of the diluted mis on the fur of her neck and rubbed it around but only around her neck and a bit on her back n belly . Is this going to kill my cat??? Ive also sprayed all the couch pillows and carpet area in front n around couch ive put sheets on the couches n chair and misted over those. Is she going to be ok evven if she licks her fur im so worried she looms fine n seems to have a bit of relief . What should i do? Its 2:41 am and im worried i made a big booboo n cant sleep i dont know where you are time zone but would greatly appreciate it if you could respond as quickly as possible im afraid shell be poisoned or sick by morning if i go to bed . Ty so much

    • July 25, 2017 / 5:55 pm

      Hi, everything should be ok! Rosemary is safe for cats, as stated in the post. Also, if she was going to experience toxic buildup of an essential oil, that’s something that would happen over months or years, not hours. Acute reactions, like allergic reactions, would happen faster, but if she seems fine I wouldn’t worry about it.

  4. Stephanie K
    June 13, 2017 / 11:08 pm

    I have read that Lavender oil is good for repelling fleas (and ticks), any advise from yourself and thoughts on Lavender oil?

  5. Mimi
    May 26, 2017 / 6:37 pm

    Thieves was not mentioned as being toxic for cats. Any advice. So far I’ve applied Coconut oil on her rear that seems lacerated or bumps from a cat fight. Is it evidence of fleas maybe? Alice is new to my household.

    • May 31, 2017 / 9:32 pm

      Thieves is not mentioned because it is a blend and not a pure oil. This blend from Young Living does contain oils that are toxic to cats including clove, lemon, and cinnamon. Coconut oil alone should be safe for your cat though. Some people even recommend feeding it to your cat to help them achieve healthy skin and fur. I can’t advise you on the bumps though, perhaps see a vet for confirmation of a cause.

  6. speedwell
    May 6, 2017 / 11:09 am

    Catnip oil, at the concentration of one ounce per pint of fractionated coconut oil, is lab-tested to repel mosquitoes on human beings (I have seen the actual study and used it myself, and it does work; I’m allergic to mosquitoes and this keeps them away). No essential oils are safe to use undiluted directly on the cat, and few are safe to use even in dilution. Yes, citronella is one of the highly toxic ones.

  7. Jaz
    April 17, 2017 / 5:56 am

    Hi, I have a cat that is hypoallergenic to mosquitoes and everything I have used to repel mosquitos doesn’t work, or ends up actually being toxic to my cat. Do you recommend an essential oils that is safe for my cat and repels against mosquitos? Also, any recommendations on how to apply it to my cat? I would keep my cat indoors but he just loves being outside :(

    • Lisa
      April 22, 2017 / 3:26 am

      Interested as well. I have been diffusing citronella but have since read it’s bad for cats and I can tell because my normally mellow well behaved cat has been ripping at the couch and peeing on things.

  8. Trish
    November 10, 2016 / 8:06 pm

    Vetiver is not mentioned and it’s highly toxic to cats

  9. October 15, 2016 / 8:31 pm

    Great info. I didn’t know that about catnip, and what cat owner doesn’t have some handy!

  10. October 15, 2016 / 11:13 am

    Interesting. There was such a unfounded backlash against using e.o.s on cats, I’d love to see the science backed up with recent research. Feel free to reach out about a possible collaboration. I was a pioneer in the field of aromatherapy 25 years ago in Canada.