Do Spiders Eat Cockroaches?

Spiders and cockroaches – two of the most despised housemates of humans. A battle between those two must be as epic as Godzilla versus King Kong – on a much smaller scale, admittedly. But who would win? Do spiders eat cockroaches? 

Yes, they do. While not every spider can consume an adult roach, among those that can are jumping spiders, American house spiders, and huntsman spiders. Cockroach-eating spiders are either those kinds that actively hunt for their prey or when they need to trap prey in their webs, have extraordinarily robust silk. 

Sharing your space with a spider friend can therefore be a form of natural pest control. Regrettably, a lot of the common house spiders are too small or week to handle cockroaches. Daddy longlegs, for example, is too timid, and their mouth is too small.

Spiders are one of those creatures that many people are terrified of, but these little, or sometimes big, creatures can help keep pests at bay. Spiders are known to eat a variety of insects. Some spiders hunt their prey, whereas many rely on insects falling victim to their webs before chowing down.

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What Kinds of Spiders Eat Roaches?

I’m sure you’re not surprised, but there are thousands of species of spiders in the world. In fact, there are over 45,000 known species. But not all spiders dine on roaches. Every species of spider has its own diet, even though they may be similar. The species of spiders that eat cockroaches include the American house spider, huntsman spiders, running spiders, jumping spiders, widow spiders, and brown recluse spiders.

Some popular house spiders include yellow sac spiders, domestic spiders, hobo spiders, common cellar spiders, and the other species mentioned above.

If you know anything about spiders, the American house spider is much smaller than a huntsman spider. So, the smaller American house spider will eat small or baby cockroaches, whereas the huntsman can eat more giant cockroaches.

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Does it Matter What Type of Cockroach it is?

What Do Spiders Taste Like

There are five common roaches that people tend to find crawling around in their homes. These species include the brown-banded roach, German cockroach, American cockroach, Oriental cockroach, and the Smokey brown cockroach.

For the most part, all five of these insects look pretty much the same, but there are some physical differences. Do spiders care about the species of cockroach? It doesn’t seem that spiders have a particular taste for one species of roach over another.

Depending on where you live will also determine the species of roach that may or may not get into your home. For example, if you live somewhere with high temperatures and humidity like Florida, you may experience more roaches than someone who lives in dry and colder environments.

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What Else Do Spiders Eat?

In addition to feasting on those creepy crawling cockroaches, American house spiders are known to eat other household pests. Some of the other pests they will eat are mosquitos, earwigs, certain moths, bed bugs, and flies.

How Often Do House Spiders Eat?

Something interesting about common house spiders is that they can go weeks without a meal if they have to. Their bodies don’t require food nearly as often as other insects and animals. Just because they don’t need to eat frequently doesn’t mean they won’t if food is available.

Spiders are very opportunistic. If insects are available for a meal, they will take the chance. So, if you have insects regularly roaming around your home, your house spider will be eating pretty frequently. While they can eat up to four times a day if food is available, this doesn’t mean they can eat a whole cockroach four times a day.

If a spider goes without food for a long period of time, you may start finding them near water sources. Typically, they get all their water from their meals, but they need to get it from somewhere if they haven’t eaten in a few days or more.

If I Have a Roach Problem, Can I Use Spiders to Solve it?

In theory, I suppose you could. If you have many roaches crawling around, spiders that eat them can help solve the problem. But remember, spiders are tiny, and if your cockroaches are bigger than them, they won’t be able to eat more than maybe one every so often.

In addition to spiders being small and not being able to eat hundreds of roaches quickly, you would need a large number of spiders to help completely solve this problem. Since you’re trying to eliminate a pest problem, you probably don’t want to be bringing in more pests. Therefore, using spiders exclusively to solve your roach problem isn’t the best move.

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How to Keep Spiders Out of Your Home

Since spiders aren’t drawn to the food we eat, the best way to keep them from entering your home is to cut them off their food sources. If you have household pests such as roaches, mosquitos, earwigs, and other pests, getting rid of them is crucial to keeping spiders away.

You can use at home pest control sprays from your local store or hire a professional if you don’t want to deal with it yourself.

Should You Kill Your House Spider?

The answer to this question is really up to you. If you don’t have household pests and are scared of spiders, then you may want to eliminate your new house guest. If the spider isn’t bothering you, it doesn’t hurt to keep it around if a roach or other insect finds its way into your home. This way, it may help take care of that pest for you.

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Do Common House Spiders Bite?

The majority of house spiders don’t pose any danger to humans or pets. They tend to avoid us completely, and even they see us, they leave us be. If the spider feels threatened, it is possible they will bite, but it’s rare. If you happen to be bitten by a household spider, you probably won’t notice unless you see it bite you.

Now, there are some spiders that can get into your home that are dangerous to humans. These include black widows and brown recluses. If you have these in your home, you’ll want to get rid of them or call a professional to help you.

Household spiders are known to eat roaches. If you don’t mind having a little spider living among you, they may protect you from ever seeing a creepy roach.

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Somebody who wants to actively implement spiders as their form of pest control has to go for larger ones. Some of these, like wolf spiders or the brown recluse, are unfortunately not the kind that anyone should let roam freely in their home! All in all, spiders are not the most effective way to deal with a cockroach infestation. 

Nevertheless, it can be said that a few common house spiders are actually quite beneficial for any home. Even though cockroaches might not be their favorite snacks, they eat other pests that can also be carriers of disease, like mosquitoes, fleas, and flies. 

Jumping spider
Jumping spider

Why Do Spiders Curl Up When They Die? 

When cleaning the places that are so difficult to reach that you only think of dusting them only once in a blue moon, sometimes you will find a dead spider between all the dust bunnies and the hair ties you thought to be lost forever. If, instead of getting rid of it as quickly as possible, you take a closer look that the spider has drawn its legs close to its body. Why does that happen? 

The reason lies within their leg muscles, or rather, the lack of them. We humans, and most other animals (those that have legs, that is), have extensor muscles to stretch out our legs and flexor muscles to draw them back in. Spiders, on the other hand, only have flexor muscles. The function that extensor muscles usually have has been replaced by a hydraulic system

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This means that their blood is pumped into their legs by their heart, causing the legs to extend. When spiders die, their heart stops pumping, and the legs resort back to being drawn close to the body. Sometimes, this causes spiders to flip over, which is why you will often find dead spiders laying on their back. 

Spider blood, a liquid called hemolymph, is also useful for the spider to locally raise the blood pressure, which helps during molting, the shedding of old skin. 

Funnel spider macro
Funnel spider macro

Do Spiders Have Transparent Blood? 

Not all animals have red blood, and spiders actually have blue blood – the blue color is not very dense, though, so the fluid often looks transparent, which results in a liquid that looks quite similar to water.  

Rather than the red blood of vertebrates, the hemolymph of invertebrates, like also snails and octopi, is rather a fluid plasma that circulates through their body – not even inside veins and arteries, but remaining in contact with tissues all the time. The protein that transports oxygen in spider blood is called hemocyanin. This protein has a copper atom at its center, which gives the blood a blue coloring. 

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In red, human blood, on the other hand, oxygen is transported in hemoglobin molecules that are present in red blood cells. Hemoglobin has an iron atom at its center – this makes our blood blue. Both hemocyanin and hemoglobin contain nitrogen, carbon, and hydrogen. 

The fact that our veins can look blue from the outside has nothing to do with the color of the blood but is actually rather a trick of the light. The white light that shines onto our skin, whether from a lightbulb or from the sun, always contains within it all colors.

Some of these do not penetrate our skin as deeply as others – blue light, instead of penetrating the skin, bounces back, whereas red light penetrates skin deeply. This is why veins appear blue rather than red. 

Conclusion

House spiders are common in most parts of the world. These tiny spiders are often so small that you don’t even realize that they’re there. Common household spiders regularly feast on cockroaches that make their way into your home. So, while you may not be a big fan of that spider that’s made a home in the corner of your room, if you hate roaches more, you may want to let that spider stick around.

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