Spider in Worm Bin – How to Clear Them Out

A large spider in a Can o Worms worm farm

I’ll be honest with you. I’m slightly afraid of seeing spiders in my worm farm. In Australia where I live, we have some of the worlds most venomous spiders such as the Redback Spider. You can understand why I don’t like stumbling upon a spider in worm bin.

I don’t really mind small spiders in the worm farm. Most spiders are harmless and are fine to leave alone in the bin. But I can’t stand the large ones, especially if they’re aggressive when disturbed.

Why Do I Have Spiders in My Worm Farm?

Spiders will keep coming back if conditions in the bin are right. Spiders prey on insects. If it gets either too wet or too dry, it’s more likely that there will be more insects. If there are more insects, spiders will likely move in.

How Do I Get Rid Of Spiders in My Worm Farm?

Here’s some tips on how to eradicate spiders in the worm bin:

  1. Worms can only eat a small amount each day. Overfeeding worms will result in excess food rotting away which attracts insects. Avoid overfeeding so that spiders have no insects to eat.
  2. Always keep the bin moist. Spiders prefer dry conditions. Give the bin a good drench if you need to bring the moisture level back up (but don’t go overboard!). Pressure hose the spiders so they know they’re not wanted.
  3. Repel spiders using peppermint, citronella, cinnamon, tea tree, or cloves. Just add a bit here and there as worms have sensitive skins and it can irritate them. You can use oils too. Spray along the sides, lid, legs etc… You can also add some Diatomaceous Earth (DE), which is fossilizd dried sediment, on top of the bedding.

Redback Spider in Worm Bin

I’ve seen a few Redback Spiders in my worm farm. Cupboard Spiders are often mistaken for Redback Spiders. They look similar but their venom is less potent. Redback Spiders are more aggressive. And a little known fact is not all Redback Spiders have a red stripe.

Identifying Spiders in Worm Bin

A large aggressive spider lurking in my worm bin

Some musuems provide a service to help identify local animals or objects. I sent a picture to Musems Victoria. They confirmed that the spider (pictured) in my worm bin was in fact a Cupboard Spider. 🙂

This is a species from the genus Steatoda, probably Steatoda grossa. There are currently 7 described species in this genus in Australia, they are commonly called cupboard spiders or brown house spiders. They can be variable in colour from having some white marks or crescents on the abdomen to no marks.

These spiders are from the same family as the Redback but are not as dangerous. Treat them with caution though as a couple of bites have caused some issues. They have no interest in people and will not seek us out but be careful if cleaning undisturbed areas which may have some webs. Don’t put your hands into anything if you can’t see what is in there or if you’re not wearing gloves.

Museums Victoria

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