Do Pill Bugs Harm Vegetable Plants?

Many people might remember playing with pill bugs when they were kids – touch these little critters, and they instantly roll into little balls. Pill bugs may have amused us in childhood, but now, they look like threats to our gardens with their tough-looking shells and steel-gray coloring. Are pill bugs considered garden pests, especially concerning vegetables and crops?

Pill bugs do not harm vegetable plants. In fact, they do not pose any significant threat to gardens because they rarely feed on living plants and crops. They only consume plant matter that is already dead, decomposed, or decaying. 

We will talk about why pill bugs aren’t harmful to your plants and what benefits they offer for your garden. I will then talk about some interesting facts about these fascinating creatures, followed by the rare instances when they could be considered garden pests. Read on if you also want to find out how to control the pill bug population in your garden. 

Why Pill Bugs Are Not Harmful to Vegetable Plants

Pill bugs are not harmful to vegetable plants because they do not eat living crops and plants. Their diet consists of decaying matter found on the ground, such as fallen leaves, flowers, or fruits. They are docile creatures that do not even bite or sting. 

Most gardeners consider pill bugs beneficial in improving the quality of the soil. Nutrient-rich soil is an essential factor in keeping plants healthy and thriving. Pill bugs do this by speeding up composting progression by processing decomposing materials found on the soil’s surface. 

Pill bugs also contribute to making plants healthier through their feces. Worms are favored by many gardeners in this department because castings are popularly known and proven to be among the most nutritious fertilizers for plants. 

This nutritional benefit is because worms eat decaying plant material, making worm castings beneficial for plants. Pill bugs have the same diet, too, so their droppings are just as nutritious as worms.

Pill Bug Diet

These omnivores get their daily sustenance from things they find on the ground. If it’s not alive, pill bugs will probably consume them. Unlike garden pests, they do not feed on plants’ leaves, stems, or fruits.

Here are what pill bugs love feasting on:

  • Soft, decaying plants
  • Rotting vegetables
  • Decomposing grass
  • Wilted leaves
  • Mulch (particularly soft mulch like straw, grass clipping, or compost)
  • Decomposing animal and insect flesh
  • Feces (their own and other animals’ or insects’)
  • Heavy metal deposits found in soil (metals like copper, zinc, and lead may be harmful to plants)
  • Fungi
  • Eggs laid by some insects.

Fun Facts About Pill Bugs

Pill bugs are oval-shaped, wingless isopods, a type of non-insect arthropods that are otherwise known as terrestrial crustaceans or, more popularly, rolly-polly bugs. They can roll into a ball to defend themselves from perceived threats when stressed or disturbed. This defense mechanism is called conglobation.

Here are some fun facts about pill bugs:

Night Owls

Pill bugs are nocturnal. In the daytime, they hide in dark, humid spots where they can rest and prepare for a busy night. These are some of the places you might find pill bugs getting some shut-eye:

  • Underneath mulch
  • Under large fallen leaves
  • In the tiny spaces underneath rocks
  • In the nooks and crannies under fallen logs or branches. 

At night, they feed on decaying plant leaves, twigs, flowers, and many other decomposing matters on the ground. These scavengers break down decomposing materials by eating them, returning the nutrients to the soil when they excrete waste.

Nicknames Aplenty

Pill bugs go by many nicknames primarily because of their ability to conglobate. People are inclined to check if they indeed form themselves into a ball when disturbed. I’m pretty sure you would nudge a pill bug with your shoe if you see one on the ground right now. 

Here are some of the nicknames used for pill bugs:

  • Rolly-polly
  • Wood shrimp
  • Woodlice
  • Chiggy Pigs
  • Doodlebugs
  • Cheesy Bugs
  • Penny sows
  • Armadillo bugs.

They’re Not Bugs

They may be called pill bugs, but they aren’t bugs. They’re members of the crustacean family, which means they are closely related to crabs, crayfish, and shrimp. They are the only crustaceans who live solely on land, which is quite remarkable!

No Peeing

Humans and animals urinate because of the body’s need to eliminate waste, particularly ammonia. Pill bugs don’t urinate because they release ammonia differently. There are small holes in their shells that are capable of releasing ammonia in the form of gas. 

Drinks All ’Round

Pill bugs drink not only through their mouths but also their backends. They have straw-like structures in their bodies called uropods, which are responsible for this unique ability. Don’t you think this comes in handy when they’re rolled into a ball and suddenly become thirsty?

Can Pill Bugs Be Destructive?

Pill bugs can be destructive to plants and vegetables in a few instances. A few of these terrestrial crustaceans here and there won’t harm your garden, but hordes of them will have an impact. Keeping the pill bug population in check is necessary if you want your plants to thrive.

Here are some rare instances when pill bugs may harm your garden:

Abundance of Mulch

Mulch gives pill bugs the moisture they need to thrive. It also affords them great shelter and effective hiding places from their natural predators. More importantly, mulch provides pill bugs with the ideal conditions to multiply. 

A large population of pill bugs in your garden will become a nuisance. Their sheer number will hamper activities in your garden. Imagine the hassle of having to work your way around clusters of them all over your garden floor. Additionally, there might not be enough decaying matter for a large horde of pill bugs, so some might consume live plant matter to survive. 

No Predators

The lack of natural predators in your garden will encourage pill bugs and most garden pests to thrive and multiply. An overpopulation of pill bugs is a nuisance to any garden. It may stir up an otherwise healthy ecosystem. Some pill bugs may also start feeding on newly sprouted leaves or the soft leaves from seedlings.

Pill bug predators include:

  • Lizards
  • Toads 
  • Frogs
  • Spiders
  • Ants
  • Centipedes
  • Birds
  • Chickens.

How To Keep Your Vegetable Plants Safe From Pill Bugs

There are many ways to keep pill bugs away from your plants and vegetables. The two most effective methods involve keeping moisture levels down and using the scent of natural elements to drive them away. Pill bugs can multiply fast, so it is essential to control their population as early as possible before it goes out of control.

Here are some tried and tested methods for keeping your garden safe from a pill bug infestation:

Morning Waterings

Pill bugs breathe through gills found in their lower abdomen. Since these crustaceans live on land, their gills must always be moist. This requirement is why they seek moisture in mulch, under rocks, and in little crevasses in the garden. Drying out their gills, even for a short time, can lead to death. 

Water your plants in the morning to give moisture enough time to evaporate. The soil’s surface will be dry at night, right when the pill bugs come out to feed. They do not like dry conditions and will look for other places to forage where it is moist and humid.

Scent Deterrents

Pill bugs use their sense of smell to travel and look for food. They use their antennae, which protrude from their head, to detect different scents in the air. By utilizing strong, pungent smells, you may be able to disrupt pill bugs’ scent trails. They will have difficulty searching for food when you disrupt their scent trails. This disruption will make them move further away from the offending smell, thus driving them away from your plants. 

Here are some distinct scents you can make use of to drive pill bugs away:


Garlic produces a pungent smell that deters pill bugs. Using this kitchen staple will be like hitting two birds with one stone since most garden pests also hate the smell of garlic. These are some of the pests you can get rid of, aside from pill bugs, with the use of garlic spray:

  • Aphids
  • Mealybugs
  • Slugs
  • Scale insects
  • Grasshoppers.

You can make a simple garlic spray to keep pill bugs away from your plants. Here is how to do it:

  1. Crush 1 tablespoon of garlic.
  2. Fill a spray bottle with 1 quart (0.95 L) of clean water.
  3. Pour the crushed garlic into the spray bottle.
  4. Shake until the garlic is well-dispersed. 
  5. Spray all over the areas you usually see pill bugs. 

If you’d like to learn more on how to make garlic spray for pest repellent, you could check this article out: How to Make Garlic Spray for Grasshopper Repellent

Oregano Oil

Oregano oil helps repel pill bugs because they don’t like the smell. It also aids in controlling the pill bug population in your garden because it affects the egg-laying capacities of female pill bugs and inhibits the development of eggs into young rolly-pollies. Oregano oil is best used as a spray since it requires physical contact to do its job.

Here is how to make oregano pill bug spray:

  1. Fill a large jar with 1 gallon (4.54 L) of water.
  2. Add 1 quart (0.95 L) of rubbing alcohol.
  3. Add 2 tablespoons of liquid soap.
  4. Add 4 drops of oregano oil.
  5. Mix well until all ingredients are well dispersed. 
  6. Pour some of the mixture into a spray bottle.
  7. Seal the jar and store it in a cool, dry place.
  8. Apply oregano oil in areas frequented by pill bugs.

Coffee Grounds

Pill bugs do not appreciate the robust aroma of coffee. Instead of throwing your coffee grounds away, scatter them on the ground, specifically in areas that serve as hiding places for pill bugs. The smell will drive them away. Like garlic, coffee grounds offer an excellent 2-in-1 deal because they are known to help make the soil more acidic – an attribute some plants will favor. 

Final Thoughts

Pill bugs may seem a bit daunting and suspicious-looking, but they are harmless little critters offering specific benefits to your garden. However, remember that the pill bug population should always be kept in check. 

Too many of them will be detrimental to your plants’ health and your garden’s ecosystem. Be prepared with your repellent of choice the minute you notice too many rolly-pollies milling about among your plants. 

Alexander Picot

Alexander Picot is the principal creator of, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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