Weevils In Oatmeal: Ways To Keep Them Out

It’s not news that bugs like weevils are one of the biggest pantry nightmares. Granary weevils in particular always have a way of showing up in oatmeal and ruining your cereal and grains.

Weevils bore holes in foods and lay eggs which develop from larvae into pupae. Their rate of maturity and reproduction also makes them annoying pests.

Moreso, it already feels squeamish thinking about the possibility of feasting on a bowl of oatmeal with weevils hovering around.

This article explains how you can keep weevils out of your pantry food as well as other relevant information you should know.

Is it safe to eat weevils-infested oatmeal?

Yes. Weevil-infested oatmeal is completely safe to eat. Weevils are not poisonous, so they do not harm humans.

Once you cook your oatmeal, the weevils, larvae, and eggs become a source of protein for your body like meat.

Live weevils in raw oatmeal is a sign that they are free of pesticides. Conversely, if you find dead weevils in your oatmeal, it is likely that it contains pesticides and may not be safe to eat.

Besides the psychological factor, there are no significant adverse effects of eating weevils.

How do weevils get into oatmeal?

Weevils are notorious insects known to infest sealed or covered food. And it can be confusing and annoying trying to figure out how they got in.

The truth is, there’s nothing wrong with your oatmeal. Just like any other pantry pests, weevils infest and feed on cereals, grains, nuts, seeds, beans, corn, and the like. Oatmeal is particularly infested by reddish-brown granary weevil.

Sometimes, these weevils naturally come with raw oats from the grain store. The problem, however, is that you can’t see the weevils if they are still in the larvae stage.

Moreover, unlike many other insects, granary weevils live and feed inside the food. The female weevils burrow into grain kernels, deposit eggs, and seal them.

When the egg fertilizes, the larvae live in and feed on the grain until they mature into pupae. The pupae or adult weevils make a hole in the grain and emit pheromones to alert male weevils of their presence for further reproduction.

Consequently, what may have been a few eggs or growing larvae becomes an army of weevils invading your oatmeal. But, as mentioned earlier, this is no cause for alarm.

How to keep weevils out of oatmeal?

Weevils’ eggs mature in as fast as 3 days. They multiply very quickly and may contaminate foods stored for a long time.

Spraying pesticides on your food is not an option and it may seem quite difficult to get rid of them.

However, if you do the following consistently, you may win the battle against weevils in your oatmeal.

1. Know what weevils are

Knowing what weevils are will make it easy to spot them in your pantry. Oatmeal weevils are called granary weevils.

These weevils are red-brownish and wingless. Because they do not have wings, they stay inside food bags or containers instead of roaming within your pantry.

Granary weevils grow up to 4.8mm long. Their body consists of a head, abdomen, and thorax.

One female granary weevil can lay hundreds of eggs that mature into adults in days. That’s why they infest food very quickly. But you can still eat weevil-infested oatmeal if you do not feel squeamish.

2. Keep your kitchen & pantry clean

The kitchen is where you do all the messy stuff. Chopping meat, doing the dishes, cooking food, trashing diets, etc. It’s easy to leave your kitchen unclean after going through the hassle of cooking.

This can attract pests and insects into your kitchen and pantry. To keep insects and pests like weevils out, you must keep your kitchen clean always.

Wash off oil and food spills from the kitchen with soap and water or disinfectants after cooking.

Also, do the dishes as fast as you can. Throw out dirty water, and clean your microwave, toaster, fridge, and kitchen tools from time to time.

3. Carefully examine foods before buying them

When you find weevils or bugs in your food, it is most likely that the food was infested before you brought it home. Always check your grains from the store and be sure there are no insects in the bags.

Return or reject bags of oatmeal (and other grains) if you notice the seal is broken. Additionally, check the expiry date and ensure they are not close to expiration.

Buying cereal and grains from reputable brands and stores can help you avoid buying low-quality products.

I’ll also advise you to buy oatmeal you can finish in a month or two. The risk of pest infestation is higher in food that sits in your pantry for long periods.

4. Store cereals and grains in airtight containers

It’s easy for pantry pests like weevils to sneak into your food through tiny spaces or holes. Leaving your food in their boxes exposes them more to this.

Invest in quality airtight plastic, glass storage, or metal containers. Mason jars and food-grade containers will come in handy for this.

These containers are available in supermarkets, superstores, and some grocery stores.

Put oats and other dry food items in these containers and refrigerate them for at least four days before keeping them in the cupboard. This helps to kill any eggs and larvae present in the cereals.

5. Heat the grains

You can prevent weevil infestation by heating the raw oat grains in the oven. Rinse the grain thoroughly with a strainer.

Afterward, heat your oven to 140°F. Put the grains on a baking sheet and bake them for fifteen minutes.

Take out the baking sheet and leave the grains to cool before transferring them to an airtight container. This also helps to kill any egg or larvae present in the oatmeal and prevents further infestation.

6. Use natural repellents

Some herbs help chase weevils and bugs away from your pantry. A good example is bay leaves. Bay leaves add fragrance to food, but weevils can’t stand the smell.

Drop bay leaves around and in the cupboard, near your containers, or even inside open bags of oatmeal and other grains. Dried bay leaves will also give the same results if you can’t find fresh leaves.

Another excellent repellant is white vinegar. After cleaning your shelves and cupboard with soap and water, take a piece of cloth and wipe through again with white vinegar. This will kill any weevils or bugs in the pantry.

You can also use the oil from cloves if it’s the first time your food gets infested. Sprinkle the oil around your pantry and cupboard and kill any weevils or bugs. Black pepper also works when you put them in grains.

The sulfur on the matchbox also repels bugs. But you must keep the matchbox out of reach of children.


What type of foods do weevils infest?

Weevils infest grains like rice, wheat, and oats.

Can weevils get through paper bags?

Unfortunately, granary weevils can chew through paper packages.

Do weevils affect food?

Yes. Weevils feed inside grains seed, thereby reducing the quality of the food.


Weevils and bugs are grain companions. It’s almost impossible to stop them from infesting oats, wheat, rice, other grains, and cereals.

While there are things you can do to help the situation, there are also things you should avoid doing.

When buying pest control agents and carrying out necessary measures, buy fresh oatmeal that you’ll consume in weeks or a month. Storing grains and cereals for long periods invites weevils and bugs to feast.

Also, keep your kitchen and pantry clean. Store oatmeal in clean, airtight containers without holes.

Thanks for reading.

Millenora has more related articles on food pests, how to get rid of them, and how to prevent them.