Do Spiders Eat Moths? Facts About What Spiders Eat

While the preferred food source can depend on the species, spiders are natural predators that will eat a wide variety of insects like moths, flies, roaches, earwigs, ants, and mosquitos.

Spiders are opportunistic feeders and are not picky, but some have definite preferences and have specialized hunting techniques that catch them a particular type of prey.

  • The diet of spiders largely consists of a variety of different insects like moths, flies, roaches, earwigs, ants, and mosquitos, although some larger species can eat small mammals, birds, and reptiles.
  • Spiders will avoid insects that they find unpalatable, like burnet and cinnabar moths
  • It is estimated that the average spider eats around 2000 insects per year.
  • Web-building spiders are more likely to eat insects like moths, while hunting spiders eat insects like grasshoppers, beetles, and crickets.
  • Spiders are generally carnivores, but there are a few species that will consume additional plant sources of food.
  • Most spiders eat every one to three days, but can go up to four or eight without a meal if there is no food source available.

What Insects Do Spiders Like to Eat?

Most spiders will only eat living or freshly killed food but are not fussy about exactly what they are eating.

The diet of a spider largely depends on its type. Passive web-building spiders feed on flying insects like moths, flies, and mosquitoes, as well as other small crawling insects like ants and earwigs that may crawl into their web.

Hunting spiders get their meals without the use of webs and will physically attack their prey when they are in their proximity. Some are “sit-and-wait” predators which will grasp insects that visit their hunting spot.

However, other spiders can actually be seen stalking, running, and pouncing on prey. Hunting spiders will eat more mobile insects like grasshoppers, beetles, and crickets.

There are some larger spider species in the wild that will eat worms, snails, or even small mammals and reptiles.

Many people are fearful about being bit by a spider, but it is important to note that humans are not a preferred food source for spiders.

Are There Any Insects That Spiders Will Not Eat?

Spiders will typically not eat insects that they find unpalatable. Burnet and cinnabar moths are two varieties of insects that are often left uneaten in spider’s webs.

cinnabar moths

What Insects Do Common House Spiders Eat?

The common house spider’s diet consists largely of pesky insects like moths, flies, roaches, earwigs, ants, and mosquitos.

Despite the fear they may induce, house spiders actually do a lot of beneficial work to help bring down the insect population in your home.

It has been estimated that the average spider will eat around 2000 insects every year.

You may want to think twice about killing the next spider you see in your home. Many of these pests that spiders feed on like mosquitos and fleas can transmit diseases to humans, so spiders may assist in curtailing the spread of disease.

Are There Any Species of Spiders That Are Vegetarian?

Nearly every species of spider is carnivorous and eats either bugs or even small animals. However, this does not mean that some spiders do not consume any plant sources.

A mostly vegetarian species of spider called Bagheera kiplingi was discovered in Central America whose primary food source is plant-sourced!

Wayne Maddison, CC BY 3.0, via Wikimedia Commons

This plant-eating spider lives in the Acacia tree and feeds on its nectar. Their digestive system has evolved to be able to process proteins, sugar, and some fats.

The Journal of Arachnology published a systematic review that found ten families of spiders that supplement their diet with plant sources like nectar, plant sap, honeydew, leaf tissue, pollen, and seeds.

There are no known species of spider that is 100% vegetarian.

What is the Difference Between What Wild and House Spiders Eat?

House spiders will typically eat everything that wild spiders do. However, house spiders’ diets may focus more on smaller insects typically found in houses like fleas, ants, earwigs, roaches, and flies.

What is the Difference Between What Wild and Pet Spiders Eat?

Spiders found in the wild have some different feeding behaviors than pets. Pet spiders get used to the daily routine of their humans feeding them.

Because of this, they typically do not move around their enclosures as much because they know they do not have to hunt.

People usually feed their pet spiders crickets, mealworms, grasshoppers, flightless fruit flies, small caterpillars, and roaches once or twice a week. They will also require a water source.

It is recommended that if you have purchased a spider from a pet store to only feed it insects or bugs purchased from the pet store as well. Only feed wild-caught spiders, wild-caught insects.

Unlike wild spiders that are a bit pickier about only eating living or recently killed prey, spiders kept in captivity are more open to consuming dead prey.

On the other hand, wild spiders are opportunistic hunters and are constantly looking for their next food source. They prefer fresher food, but they have a tendency to be less picky about the meal is.

Do Spiders Drink Water?

Spiders generally do not need to drink water as frequently as humans do, but they do have a need for water. However, their water source is usually derived from their prey itself and is also produced as a by-product of their metabolism.

The longer they go without eating, the more necessary water becomes. Spiders will typically hang out around water sources for this reason.

How Often Do Spiders Need to Eat?

Unlike humans, spiders do not require three meals a day! Spiders are opportunistic feeders, meaning that their meal frequency depends largely on the type and availability of prey.

Most spiders typically fall into a pattern of eating every one to three days. However, if food is available, they can eat up to four times per day.

Spiders are “poikilothermic”, meaning that they are unable to manage their body temperature on their own, except by behavioral means such as basking or burrowing.

Due to this, spiders have the ability to go dormant, which significantly reduces their metabolism and thereby requires little to no food.

After eating a good amount of prey, spiders are able to go up to four to eight weeks without another meal.

Larger species can typically go longer without eating than smaller spiders, which have higher metabolisms, so they need to eat more quantity-wise.

A prolonged period of starvation past this four-to-eight-week period may lead to the spider’s death.

In Conclusion

Killing on average around 2000 insects per year, spiders are an excellent form of pest control – both in and outside the house.

They are largely carnivorous and eat a wide variety of pests including moths, mosquitoes, flies, fleas, ants, earwigs, and roaches.

They have the ability to consume numerous pesky insects every day that can contribute to disease transmission in humans.

Depending on the species, they can hunt with or without webs. They are hardy little creatures that can either eat every day or go up to eight weeks without food.

So maybe you may want to think twice about the next time you go to kill a spider in your bathroom!

Alright, that’s it for this article, here are a few hand-selected articles that you might also find interesting reads:

7 Super Important Things Spiders Do For Us

How Long Do Pet Spiders Live? 7 Popular Breeds Covered

7 Unexpected Things Spiders Do In a Typical Day

Steve Foster

Mad about bugs and wanting to publish as many articles as I can to help educate people about these amazing beautiful creatures! For more info check out my about page

Recent Posts