What Do Worms Eat? Feeding Worms and What You Need to Know

What do worms eat? Start with fruit and vegetable scraps.
What do worms eat? Start with fruit and vegetable scraps.

Understanding the basics so you can feed worms properly is vital to the success of a worm farm. This also includes what food is added, the quantity, preparation and placement in the bin. And if you do make a mistake, several worm farm problems such as a bad smell or a toxic environment can arise. So what do worms eat? Worms will eat anything organic. However, there are some foods you should avoid.

What Do Worms Eat – The Basics

Worms thrive on a balanced diet and prefer to eat their food as it begins to decompose. Keep a balance of green and brown foods.

Feed your worms fresh fruit and vegetable scraps. Limit foods high in acidity. Worms also don’t like strong flavors, such as citrus, garlic and onion. Be careful that fruit has no insecticides on it as this can kill your worms

Eggs shells give worms grit to break down foods and also helps to neutralize the pH levels in the bin.
Eggs shells give worms grit to break down foods and also helps to neutralize the pH levels in the bin.

Add egg shells. This helps to neutralize the pH levels in your worm bin. You can also add agricultural lime if needed. Egg shells are high in calcium as well which is beneficial to the worm farm. Feeding worms a lot of fruit will increase the acidity in the bin due to its the high sugar content.

Shredded newspaper makes excellent worm farm bedding material
Shredded newspaper makes excellent worm farm bedding material

Add carbon for worm bin bedding including shredded paper, egg cartons and cardboard. When in doubt, add more paper. Paper and cardboard should be shredded and soaked in water first.

Avoid feeding worms meat, dairy, and oils. While worms will eat meat and dairy products, these foods will create a bad odor and attract pests.

Don’t offer salty or spicy foods, or foods with preservatives. Worms breathe through their skin, and certain food can irritate that process

Add grains and grain products in moderation. Grains should be ground up before adding into the worm bin. Be careful not to add too much as grain may attract rodents.

The Ultimate Worm Farm Guide for Beginners

Are you thinking about starting a worm farm? This guide will teach you everything you need to know about how to start a worm farm.

Worm Farm Food List – What Do Worms Eat?

Here’s a list of what to feed worms, and what not to feed worms:

Add dry garden leaves into your worm bin.
Add dry garden leaves into your worm bin.
Source: thealternative.in

What do worms eat? Add:

  • Kitchen greens and vegetable scrapings
  • Potato and other vegetable peels
  • All fruit
  • Crushed egg shells
  • Shredded paper and cardboard
  • Hair and nail clippings
  • Cotton rags
  • Leaves
  • Cereals
  • Grain and grain products
  • Tea bags and coffee grounds
  • Moldy bread
  • Horse and cow manure, this is the worms natural diet and they thrive on it

Do not add (or avoid):

  • Meats, bones, fat and anything oily or greasy – but natural oils (e.g. avocado) are fine
  • Dairy products including butter, sour cream, milk, whole eggs (egg shells are OK) and cheese
  • Canned sauces, peanut butter and other processed food
  • Citrus foods like lemons, limes and oranges
  • Pineapple contains an enzyme that will kill your worms
  • Onions and garlic – although onion skins are OK in moderation
  • Spicy foods such as hot peppers
  • Yard trimmings treated with pesticides
  • Plastic, metals, glass or other non-biodegradable items
  • Soap
  • Paper that has a glossy finish or colored ink
  • Poison ivy, oak or sumac or other poisonous plants
  • Grass

List of Bad Foods for Composting Worms

Here’s a list of foods to avoid when feeding worms:

Food Reason
  • Smells and creates heat when breaking down
  • Attracts rodents
Grease and oils
  • Makes it difficult for worms to breathe through their skin
  • Can burn worm skin
  • Smells when breaking down
Onions and garlic
  • Acidic
  • Smells when breaking down
  • Acidic
  • Acidic
  • Contains Limonene which slows down decomposition
  • Toxic for worms
Pineapple & Papaya (Pawpaw)
  • Acidic
  • Contain enzymes that can kill your worms
  • Acidic
  • Tends to go hard and dry
  • Attracts potworms and allows them to breed up.
  • Attracts rodents
Rice and pasta
  • Attracts rodents
  • A lot can heat up
  • Heats up and gives off ammonia, both of which can kill your worms

Some bad foods such as bread are OK to feed to worms in small quantities, as long as you’re adding a relative amount of good foods as well. Moreover if you’re unsure about whether you should add specific food source, then always leave it out.

What Do Worms Eat in My Bin?

Here are the top foods I add into my bin:

  • Fruits with high water content like watermelon, cantaloupe and mango peel. My worms go mad on these.
  • I regularly mix in coffee grounds. Never a shortage 🙂
  • Banana peels for extra carbon and to create a canopy keeping the under cover and dark.
  • Occasionally I add egg shells for calcium. Worms always curl up inside.
  • Strawberry and cucumber are popular too.
  • Cardboard (thanks Amazon) and shredded newspaper
  • Small amount of grass clippings after mowing lawns – helps to raise temperature in Winter
  • Apple cores (my son eats about 2 apples a day)
  • Carrot tops

I have a small bucket in my kitchen to collect food scraps. And when it gets full, I curate and divide the contents between a couple of worm farms. And then I put everything else in a hot compost bin.

I like to keep things simple. I don’t cut up or freeze food scraps. If something is too big, I chuck it in the hot compost bin.


Be aware of the water content of foods that you add into the worm bin. Cantaloupe for example is 90% water.
Be aware of the water content of foods that you add into the worm bin. Cantaloupe for example is 90% water.

Worms eat about half of their body weight each day. However, when starting a new bin, this rarely happens straight away as they need some time to settle in. Your worms may take a week or two to adapt to the new environment, so don’t expect them to be 100% productive.

1000 worms is approximately 1 pound or 500 grams in weight. So if you have 1000 worms, you would need to feed them half of this weight each day (i.e. 1/2 a pound or 250 grams each day). Also be aware that worm populations will increase under favorable conditions given sufficient food supply and space. In very general terms, a Red worm population can double in number approx every 60 to 90 days.


Feed your worms once their last meal is nearly gone. Overfeeding worms is the single biggest cause of problems in a worm bin. If the bin contains too much food, the food scraps will begin to rot before the worms can digest them. In addition, this can lead to a toxic environment. It is better to underfeed your worms than overfeed them.

Rotate feeding worms in different sections. This is also called pocket feeding.
Rotate feeding worms in different sections. This is also called pocket feeding.

One way to prevent overfeeding worms is to add food scraps in small amounts and in one place at a time. Some people like to alternate sides when adding food scraps into the worm bin. Or they rotate adding food to different sections in the bin. For example, add food scraps to section 1, then a few days later repeat and add food scraps to section 2 and so on.

Water Content

You should also consider the water content of foods that you add. Feeding too many high moisture foods such as zucchini and watermelon can cause a worm bin to become too moist.

Carbon-to-Nitrogen Ratio

Worms like to eat foods just as it begins to decompose. The rate of decomposition of organic materials is greatly influenced by carbon and nitrogen. For worm composting, conditions are generally ideal with a carbon-to-nitrogen (C:N) ratio of between 20:1 and 35:1.

Materials high in carbon (C:N ratio greater than 30:1) are categorized as browns because they are dry. And nitrogen rich materials are categorized as greens because they are fresh and moist (C:N ratio less than 30:1).

If you add equal amounts of greens and browns into the bin, then the C:N ratio should take care of itself. So it’s a good idea to have a basic understanding of what is a green or brown when adding food into the bin.

C:N Ratio Calculator


C:N Ratio List

Wood chips have a C:N ratio of approx. 400:1
Wood chips have a C:N ratio of approx. 400:1 Source: daviddomoney.com

Here’s some estimated C:N ratios of various worm food sources:

  • Garden waste 25:1
  • Vegetable scraps 12:1
  • Food scraps 15:1
  • Manures 15:1
  • Fruits 25-40:1
  • Coffee grounds 20:1
  • Grass clippings 20:1
  • Fruit waste (e.g. banana skin) 35:1
  • Peat moss 58:1
  • Leaves 60:1
  • Straw 75:1
  • Shredded newspaper 175:1
  • Wood chips 400:1
  • Shredded cardboard 350:1
  • Sawdust 325:1


Not only do you need an understanding of “what do worms eat?”. You should try and optimize worm farm food for their consumption.

Worms do not have any teeth. This means they need to wait until the food begins to rot or break down so that it is soft and wet enough for them to eat. So it’s good to cut up your food scraps into small pieces so that they can digest it faster.

There are a couple of other ways you can prepare food and make it easier for worms to consume. You can puree, grate, freeze, or microwave food scraps to help break down the material. And remember to make sure that food has returned to room temperature before adding it to your worm bin.


Cover new food scraps with a mix of bedding and paper or use worm blanket. This keeps it dark and moist, encouraging the worms to come up to the surface and feed. This will also discourage pests such as fruit flies.

Outdoor Compost Bin

Having both an outdoor compost bin and a worm farm work well together. For instance it’s better to add less preferable foods (e.g. harder and more acidic) into an outdoor compost bin rather than in a worm bin. And if you have more food waste than the worms can handle, then topping up the outdoor compost bin is a great option.

Common Questions

Do worms eat lettuce?

Yes worms will eat lettuce. Lettuce is high in water content and rich in nitrogen; similar to grass clippings. Avoid adding large quantities of lettuce in your worm farm as it will heat up as it breaks down.

Do worms like bread?

Worms love eating little bits of bread. But it is best to avoid adding bread into your worm bin. Bread tends to go moldy and starchy foods including bread, pasta, rice etc… will attract large populations of potworms.

5 thoughts on “What Do Worms Eat? Feeding Worms and What You Need to Know

  1. often I read that worms eat 1/2 there weight in food daily, that being under ideal conditions.
    I tend to puzzle a bit over the moisture content. Assuming an average of 80% MC of food scrape. 1/2 lb of food is 6.4 oz water and 1.6 oz organic matter.
    Do you take MC into account when using the (1/2 there weight / day) equation??

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