Can Fleas Drown in Water?

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Since Mankind first decided to take shelter from the elements, we have had to deal with other critters trying to take advantage of us. The rise of common pests became so bad that it led to the bubonic plague wiping out 1/3 of Europe. We now know the particular pest responsible, and they happen to still infest our homes to this day. We’re talking, of course, about fleas.

There are actually many different types of flea, with the cat flea being the most common. But all fleas share some common traits, including a body that’s very difficult to squish.

So today, we’re going to look at one way people try to kill fleas – by drowning them. Does this work? Can fleas swim? Let’s examine the many questions and kill methods associated with water to find out…

See Also: Can Bed Bugs Survive in Water?

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Can Fleas Drown?

Technically speaking, yes, fleas can drown. In fact, all critters can drown, even fish in the right circumstances.

However, just because something can happen doesn’t always mean it’s likely. Fleas and a lot of other tiny pests aren’t always easy to drown, and simply tossing one in water won’t be enough to kill them.

Can Fleas Swim?

Fleas cannot swim, but the reason for this is also the reason why it’s very difficult for them to drown.

The body of a flea has flat sides, and when dropped onto the water’s surface, their body is very light and coated in a hydrophobic wax, so they’re unable to break the water’s surface tension. As a result, they simply lay there flailing around in the hopes of finding purchase on a solid object so they can escape.

A flea can survive up to a week while stuck on the water’s surface.

Do Flea Eggs Drown?

Flea eggs don’t move, so how can you tell if they’re killed by water? Well the truth is that a flea egg can survive for several days when submerged in water. Thus, if you simply dislodge them in the tub or toss them in a bucket of water, you aren’t going to kill them.

Flushing them or washing them down the drain may or may not result in killing the eggs, as it would depend on whether the egg ends up submerged in the sewers or if it ends up on debris.

Can Flea Larvae Drown?

Thankfully, flea larvae are another matter entirely. The larvae feed on flea dirt, which dissolves in water, so simply hosing your pet down can temporarily rob them of their food supply. Additionally, flea larvae are adapted to survive in slightly moist soil (an adaptation they haven’t lost once they began invading homes).

If the soil moisture exceeds 20%, the larvae will drown. In fact, being submerged in any amount of pure water can kill flea larvae within 24 hours.

Read Also: 15 Bugs That Are Often Mistaken For Fleas

Will Flea Cocoons Drown in Water?

Rounding out the flea life cycle is the cocoon. The pupal stage of fleas isn’t as vulnerable as the larval stage, but it’s still  much less resilient than the adult stage.

When submerged in water, approximately 38 percent of flea cocoons will drown. It can take up to a week to kill 100 percent of the cocoons, though. This has more to do with the pupae being partially developed adults than the cocoon itself, which isn’t waterproof.

How Long Can Fleas Survive in Water?

This depends largely upon the type of water they end up in. As mentioned earlier, eggs can survive in water for up to four days, adults up to a week, but larvae will die within 24 hours. However, if the water has no surface tension, an adult flea can drown in about 24 hours.

Additionally, poking a flea beneath the water’s surface isn’t enough to make them drown, due to being lighter than water.

Can Soapy Water Kill Fleas?

sudsy water

This is a bit more complicated than it first seems, as soapy water can both speed up drowning and prevent it. Let’s take a bit of a deeper dive into just why this is.

When soap mixes with water, it acts as an emulsion, meaning the soap causes the water to lose its surface tension. This is why you can mix oil and water if you add a touch of dish soap.

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Without surface tension to keep them buoyant, the fleas will sink despite their minimal weight. It will still take up to 24 hours for the flea to drown, but that’s far better than seven days.

But there’s a potential drawback to soapy water as well that can actually prevent fleas from drowning. When soapy water is agitated, it can produce bubbles. Fleas are small and light enough that they can actually grab onto a soap bubble and use it as a life preserver. Once safely on the bubble, the flea can leap to safety.

Read Also: Does Soapy Water Kill Wasps?

Water-Based Kill Methods (and Their Effectiveness)

As you can see, water can kill fleas, but it takes a long time to kill certain stages. The good news is that mixing water with other ingredients can prove far more effective. Let’s round off the conversation by covering several of these water-based methods.

Essential Oils

cedarwood essential oil

Water is often used to dilute essential oils and act as a carrier. Adding a few drops of Dawn dish soap can help the oils stick onto surfaces. You’re probably already familiar with the idea of mixing these three ingredients for use in the home and garden. What you might not know, however, is that some essential oils will actually kill fleas.

Adding a few drops of cedarwood essential oil to a spray bottle full of water can make a safe and effective flea killer you can spray directly on dogs (always use caution when working with cats, as they are far more sensitive to essential oils).

A spray using clove essential oil cannot be applied directly to your pet, but it can be used on collars or bedding to kill fleas.

Most other essential oils (including lemon) can repel fleas but won’t actually kill them. Also, you should never use pennyroyal or tea tree oils, as these are highly toxic to cats and dogs. But when it comes to a few drops of cedarwood or clove oil in a bottle of water, you’ll end up with a surprisingly effective treatment.

Bucket Tricks

If you’re feeling sadistic and have a little time on your hands, there are some ways you can kill fleas in a bucket of soapy water. You’ll want to use a dishwasher-style detergent, such as Finish, as these don’t produce suds.

Lube up the inner wall of the bucket with some petroleum jelly so the fleas have nothing to grip onto. Now when you pluck them off of your pet and toss them into the bucket, they’ll be trapped and will drown over the next 24 hours.

A related trick is to use vegetable oil instead of soap. The surface tension of vegetable oil is only half that of water, and (because it’s an oil) will float on top of the water in a thin slick. Because vegetable oil is so viscous, the fleas will be unable to move and will sink below the surface, resulting in them drowning much quicker.

See Also: Does Rubbing Alcohol Kills Fleas?

Flea Baths

flea bath cat

We should probably mention this water-based treatment method, even though it’s not a home remedy. Flea shampoos (like Adams Plus) contain a number of ingredients that kill adult fleas on contact, as well as interrupting the ability of eggs and larvae from reaching the next growth stage.

You’ll need to repeat the process a few times to completely eliminate the fleas, of course, and you should always start by washing the face and neck so fleas won’t attempt to hide in your pet’s ears and nose. Best of all, the fleas you see in the water are already dead.

See Also: Can Fleas Live In a Person’s Hair?


Heat can be one of the most effective killers out there. Owning a high quality steam cleaner means you’ll have a deadly weapon to tackle almost any insect pest out there, including fleas, bed bugs, and carpet beetles. You will generally want to own one marked for commercial use, as these tend to have a higher temperature range than domestic models, although they also cost more.

To kill a flea with heat, it will need to be at least 180 degrees. The good news is that heat is a pretty fast killer, cooking fleas alive in a matter of minutes and removing both their carcasses and plenty of dirt from various surfaces in the process.

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Washing Machine

Your washer is a giant box of death for fleas. Many fleas will get trapped in the folds of your clothing as your washer fills, preventing them from floating on the surface tension. The soap then breaks down that very surface tension.

The heat from the water begins cooking trapped bugs slowly. Finally, it hits the next cycle and the water is agitated, knocking the fleas about so there’s no escape. Those few exhausted fleas that manage to survive the washer will be finished off once you transfer your clothes to the dryer.

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3 thoughts on “Can Fleas Drown in Water?”

  1. Thank you, Morgan! This information has helped me tremendously. I felt so useless not knowing how to fix the flea problem in my home. We have a small dog, very loved, however, the fleas were causing me headaches. Now I feel more in control. Forever grateful. Mary

  2. I have 5 dogs all have fleas
    We have tried everything from topical, flea collars, sprays and chewable meds. My dogs are losing all of their fur and it is extremely depressing to see your fur babies hurting.
    I look forward to trying some of these methods.
    Thank you


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