Do Spiders Eat Caterpillars? Are They Safe?


While the diet of spiders varies depending on the species, most spiders eat a wide range of insects. This can include both hard-bodied and soft-bodied insects, as well as other small arthropods. But, do spiders eat caterpillars?

Yes, in some rare cases, spiders can eat caterpillars! However, it’s not their preferred food source, and some caterpillar species can be poisons to spiders if eaten!

In fact, there are around 180,000 species of caterpillars, and not all of them are safe for spiders to eat. But, don’t worry in this article we will tell you the types of caterpillars that are safe for spiders and the ones you should avoid. We will also share some juicy alternatives that your spider will enjoy even more!

Should You Feed Caterpillars To Your Pet Spider?

If you find a caterpillar in your garden and you want to feed it to your pet spider, Is this a good idea? The short answer is no! While there are some spiders that will eat caterpillars, it’s not a good idea to feed them to your pet spider for a couple of reasons:

  • Some Caterpillars Can Be Poisonous
  • Some Caterpillars Can Carry Pesticides

For example, the fuzzy hickory tussock moth caterpillar “also known as the “black and white tussock caterpillar” and the Swallowtail Caterpillar is very poisonous and can cause serious health problems for spiders if digested.

Some caterpillars can even carry pesticides! For example, if you’ve found a dead caterpillar in your garden and it’s recently been in contact with pesticides, these chemicals can be transferred to your spider.

Important: If your not sure about the type of food your spider eats always consult with your local vet or pet shop and they can advise you further and even give you alternatives!

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Spider Eating A Caterpillar

Types Of Caterpillars That Are Safe For Spiders

In the wild, spiders will eat just about any type of caterpillar they can catch. However, the most common types of caterpillars that spiders will come across and eat are:

  • Cabbage Loopers
  • Cabbage Worms 
  • Codling Moths
  • Corn Earworms
  • Pickleworms

The thing you need to remember is, pet spiders have different tolerances to caterpillars than wild spiders! So even though these are safe for spiders in the wild, for spiders in captivity, this is another story, and they may react differently.

What Size Caterpillars Is Safe For Spiders To Eat?

While some spiders specialize in capturing small prey, others have no problem taking down much larger prey items. So, what size caterpillar is safe for spiders to eat? In general, spiders can eat any size of a caterpillar.

However, there are some exceptions. For example, the black widow spider is capable of eating prey items that are up to five times their size! But while they can eat larger prey items, they typically stick to smaller insects.

So while spiders can eat caterpillars of any size, it’s best to stick with small insects if you’re looking to feed your pet spider. These are a much safer and healthier option for your spider!

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How Many Caterpillars Can They Eat?

Spiders will only eat one caterpillar at a time! however, when spiders immobilize their prey, the first thing they will do is wrap it in silk! not only does this make it easier to subdue “but” also acts as a food storage system.

Wrapping their prey in silk keeps it fresher for longer, which is important for spiders who only eat every few days.

In addition, the silk acts as a sort of insurance policy, ensuring that the spider will still have food if there is a shortage of food.

How Do Spiders Eat Caterpillars?

Most spiders are venomous, and they use this venom to immobilize their prey. Once the caterpillar is paralyzed, the spider will wrap it in webbing and then sink its fangs into the caterpillar’s flesh.

The spider will inject digestive fluids into the caterpillar’s body, liquefying its insides. The spider then sucks out the caterpillar’s liquefied insides, leaving only an empty husk behind.

While this may sound like a gruesome way to die, it is actually quite efficient for the spider. By liquefying its prey, the spider can extract a greater amount of nutrients, making each caterpillar a more valuable meal.

Alternatives To Caterpillars

While it’s true that spiders will eat caterpillars, it’s simply not worth the risks! However, there are alternatives that are much healthier for your pet spiders.

  • Mealworms: Mealworms are a good source of protein for your spider and are easy to store and care for. They can be purchased live or dried from most pet stores and they will last for months if stored properly.
  • Grasshoppers: Grasshoppers are very nutritious for spiders and are high in protein and fat, which helps spiders grow and maintain their energy levels. Grasshoppers are also a good size for spiders proving that perfect meal.
  • Crickets: caterpillars are often praised for being an excellent source of food. They are packed with nutrients and moisture, which is essential for keeping your spider healthy and hydrated. In addition, caterpillars are easy to find and relatively inexpensive.


So there you have it! spiders can eat caterpillars, but it’s not their preferred food source. If your worried about giving your pet spider caterpillars, then you should avoid feeding them to your pet spider.

You can also contact your local arachnid or pet store for more information on what types of caterpillars are safe to feed your spider. They will be able to give you specific advice based on the type of spider you have! Thanks for reading!

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