Can Spiders Drown in Hot Water?

You’ve probably heard the rumor before that you can drown spiders in hot water and wondered if it was true or not?

Spiders can drown in hot water. But remember that this technique affects spiders depending on their types and the temperature of the water.

In this comprehensive guide, you’ll find out how this common spider-killing technique works and why spiders are so sensitive to hot water in the first place.

What Happens When Spiders are Submerged in Hot Water?

Spiders generally love water as they tend to look for it under your sink, inside your bathtub, and sometimes in your drain to stay hydrated.

There are species of spiders capable of swimming and staying underwater for long periods and only need to dash back up to the surface to catch some air.


It is a fact that spiders are proficient in adapting to water temperature. That is why lukewarm and tepid temperatures won’t kill spiders (at times).

Just like human beings, spiders may only feel uncomfortable when submerged in lukewarm water, but it won’t kill them.

Spiders have light body mass with waterproof hair covering their body, so they can float and swim for their lives.

In short, the hotter the water, the more chance of death. But why would you do that to a little insect!

Lots of spider species originated in warmer climates, but this does not mean that they love being in hot water.

For instance, boiling water is a sure way to kill spiders. Combined with the force and boiling temperature, immersion in hot water causes spiders to become disoriented and ultimately drown.

Again, I need to address that it is cruel to pour boiling water on spiders. Because using hot water will inflict a lot of pain on his tiny body. Although often seen in our spaces, spiders do not have any intention of hurting humans.

There is a good chance that these insects are only looking for water to hydrate their body.

Another possible reason is that spiders love warm spaces, which is why we often see them in our garages and places in our houses where it is humid.

Will Heat Kill Spiders?

Given that spiders love to feel warm dealing with hot scalding water is another topic. In contrast to what most people think, scalding water does not kill spiders immediately.

It will only cause them to feel immense pain as the hot liquid will start to cook them alive.

The good news is that there are other ways of killing spiders without having to resort to such cruel methods.

For instance, you can use a cup to trap the spider and then flush it down the toilet. You can also use a broom to sweep it outside your house.

boiling water

If you must resort to using hot water, make sure that the water is at least boiling before pouring it over the spider.

Factors That Affect How Hot Water Kills Spiders

Always remember that not all species of spiders can swim.  If, by any chance, you see a spider around the waters, it is possible that it is just drinking. So, submerging them in water – especially hot water is not a good idea. Here are some factors in how hot water can kill spiders.

The Water’s Temperature

Spiders by their nature, can quickly adapt to dry and hot conditions as they came from warm origins. But this does not mean that they can survive in boiling water.

If you want to drown a spider using hot water, make sure that the water is at least 160F.

If the water is between 110 to 120 degrees Fahrenheit, then the spider will have the highest chance of surviving.

They may be able to accumulate some injuries, but they will not die in hot water within this temperature range.

The Spider’s Size

Spiders are small insects, and if they are flushed or submerged with water, they will end up drowning. But spiders won’t die in an instant even if you use hot water.

This has something to do with the size of their body and their metabolic rate.

The larger the spider, the longer it can survive in water. If a spider is submerged in hot water and has a body size of less than one-quarter of an inch, then it will die within 20 minutes.

On the other hand, if the spider is one to two inches long, it could take up to two hours before they drown.

The Spider’s Species

Some spiders can do well in water.  Diving Spiders, Raft Spiders, Dock Spiders, or Wharf Spiders commonly seen in Northern America are just a few of the names on top of the list.

These spiders can stay under the water for extended periods.

Some species of spiders can build air pockets that will help them to survive in water. There are also those that can trap air bubbles under their abdomens to enable them to breathe while submerged.

While some of these species of spiders can survive in water, they will still eventually drown if they are submerged for an extended period.

Whether the Spider Can Climb Out of the Water

There is still a chance that a spider may survive once it has been drenched in the middle of a body of water. But this is only if the spider has the capacity to climb out of the water.

In some cases, spiders use their 8 legs to evenly distribute their weight. Doing so allows them to slowly cruise on the surface of the water.

The Duration of Immersion

The length of time that a spider is submerged in water will also affect whether it drowns or not. If a spider is only exposed to hot water for a few minutes, then it still has a chance of survival.

The more extended the exposure, the higher the possibility of death.

spider immersed in water

Final Thoughts

In conclusion, it is true that spiders can drown in hot water and slowly kill these insects in the process. Combined with the force and heat of the water, a spider will eventually die from trauma and drowning.

There are also different factors that affect the process of how hot water can kill spiders. However, there are other ways if you want to get rid of spiders inside your space.

Remember that spiders do not intend to hurt humans, and it is only humane to let them be free outside.