Our dogs are curious and inquisitive creatures. They also love to put random things in their mouths and a dog eating something you haven’t seen on your lawn can cause panic. What if it was army or grub worms? Are army worms harmful to dogs?
Dogs eating these caterpillar-like moth larvae with dark and light stripes on their body’s, is generally not harmful, but there are a few risks.
The below guide covers all the info you need to know about why army worms aren’t harmful to dogs (generally), when they can pose a risk to your pup, and how you can get rid of these pesky grubs and caterpillars!
- Army worms aren’t harmful to dogs on their own.
- An army worm won’t poison your pet dog if it eats or touches the insect, but may cause parasite and worm infestations in your pup.
- You can get rid of army worms by removing them from plants and grasses and placing them in soapy water.
- You might want to spray plants with a natural insecticide to keep them out of your dog’s reach.
- Army worms last for between 16-40+ days depending on the temperature, after which they enter a pupal stage, emerging as a fully grown moth.
Can Army Worms Hurt Dogs?
No, army worms cannot hurt dogs in isolation but there are some risks if your dog manages to eat one (more on why a little later.)
For example, army worms won’t bite an inquisitive dog that gets too close, while caterpillars lack any stinging ability.
Furthermore, army worms aren’t toxic, so any dog that eats them won’t suffer from any health issues.
Some dogs may even enjoy the experience of hunting and catching army worms, which may be why your pet loves eating them around the garden.
In fact, caterpillars and larvae are regarded for their high protein, making them a sought after snack for dogs, albeit one they probably should avoid eating.
The reason for this is, while they’re not directly harmful to dogs, the risk comes when your furry friend eats grub worms or armyworms which have been infested by parasitic worms which can then be passed on to your dog.
DID YOU KNOW: Despite the name, army worms aren’t even worms, rather being the larval stage of several different moth species. They are often lumped in with grub worms as they are both pests to various grass species, though they are different (grub worms are beetle larvae).
Are Army Worms Poisonous to Dogs?
No, army worms are not poisonous to dogs.
Army worms don’t bite or sting dogs, making it impossible for them to poison your pet.
Furthermore, while certain caterpillars are toxic to dogs, army worms aren’t, so your dog won’t be poisoned should they eat or touch the insect.
However, eating any type of army worm or grub worms comes with a risk to your dog.
While, they’re not poisonous, they do burrow through soil which the worms ingest and this can mean crawling through toxic chemicals or attracting intestinal parasites.
Roundworms also commonly lay eggs which can be picked up by grub worms and these can make your dog sick.
There are certain caterpillars that are dangerous if dogs eat or touch them, typically several species that have distinct hairs or spines across their bodies.
For example, the saddleback caterpillar has hairs that secrete venom, while the buck moth caterpillar has hollow spines attached to poisonous sacks.
Thankfully, armyworm species or grub worms don’t have hairs or spines that can poison your dog, but should still be avoided for the risk of parasites.
DID YOU KNOW: while many types of worms and larvae aren’t harmful to dogs, hammerhead worms may be harmful to dogs!
What Type of Grass are Army Worms Attracted to?
Armyworm damage can include up to 300 different plant species!
Here are the most common turf grasses they like to eat:
Cool Season Grass
- Axonopus (Carpet grass)
- Cynodon (Bermuda grass)
- Paspalum (Bahia grass and Seashore paspallum)
- Zoysia (Zoysia grass)
Warm Season Grass
- Perennial ryegrass
- Kentucky bluegrass
- Tall fescue
- Fine fescue
Fall armyworms will attack both warm season grasses grown and cool season types as they become most active from temperatures above 65 degrees F.
Fall armyworm invasions are most common in August through October, but in periods of drought, they can be spotted as early as July.
How to Get Rid of Armyworms and Keep Them Out of Your Dogs Space
There are a few options you can use to get rid of an armyworm infestation including:
- Introducing beneficial insects: such asladybugs, lacewing, minute pirate bugs and rove beetles. These insects eat armyworm eggs and young larval stage armyworms
- Spray plants with a natural pesticide or insecticide treatments: check the product, so that it won’t be harmful to your dog or other insects
- Soapy water: manually find army worms and place into a bucket of soapy water (any liquid soap will work) to kill it.
- Introduce natural predators: If you can attract ants, they like to eat armyworms and birds also like to feed on them
- Mow lawn regularly and remove grassy weeds: not only does this create a less attractive environment for moths to lay their eggs (the prefer grasses that are longer), it creates a better environment for your beneficial insects too.
Like all caterpillars and larvae, army worms love to eat, with the sole purpose of the larval stage being to gather enough food until they’re ready to pupate.
As a result, army worms have a massive appetite and aren’t fussy eaters – they’re known to eat over 300 different plant species!
In fact, an armyworm infestation is a huge problem for farmers, causing devastating economic damage, destroying fields of crops as they eat through the leaves of plants.
So, if you spot army worms in your garden, you may want to act fast to ensure they don’t destroy any of your plants and cause significant damage!
Getting rid of the destructive armyworm may take time and effort, as you’ll want to remove them directly from any plant you see them on.
Before you begin: make sure you have identified armyworms correctly. They’re surface feeders and not to be confused with grub worms, who cause major damage to lawns from beneath your grass or plants. Refer to our ultimate guide on how to get rid of grub worms from your garden, in this case.
Army worms are most active during the early hours and late evenings, so be on the lookout at these times for the best chance to spot them feeding on your plants, usually on the underside of leaves.
Once you find an army worm, simply place it into a bucket of soapy water (any liquid soap will work) to kill it.
Of course, this can be a lot of work, so another option is to spray plants with a natural pesticide that won’t be harmful to your dog or other insects in order to control armyworms.
Though there is an interesting study focussing on armyworm control through insect viruses that only affect them, without harming beneficial insects.  It will be interesting to see how that development progresses.
Another great way to get rid of army worms in your yard is to encourage their natural predators to visit your outdoor space.
For example, birds enjoy eating caterpillars, so you could try to attract more birds using birdfeed or planting trees and shrubs to assist with your armyworm problem.
Taking action early is always better to prevent army worms.
We have a complete guide on how to get rid of army worms from your lawn.
How Long do Army Worms Last?
As army worms are in the larval stage of their life cycle, they only last for short period before entering their pupal stage, after which they emerge as fully grown adult moths.
Fall armyworm moths usually complete their life cycle and emerge after 30 days in the Summer and up to 60 days during spring and autumn.
Factors such as the outside temperature impact how long army worms remain in their larval stage.
For example, cooler conditions of around 60F often cause army worms to last longer, anywhere up to 40 days in their active form.
In this climate, you’ll get species that feed on cool season grasses like fescue.
Conversely, warmer temperatures usually reduce army worm larval stages, often as little as 16 days for temperatures in the 80F range, where they feed on warm season grasses.
So, expect these destructive pests to last anywhere between 16-40 days depending on the consistency of temperatures where you live.
While army worms are a pest for farmers and gardeners, they don’t cause any harm to dogs that may ingest the caterpillar.
Certain caterpillars and larvae are toxic to dogs that touch or eat them, but army worms pose no such risk.
The risk for your dog is being infected by parasites that mature larvae have picked up during their feeding period.
Army worms last for anywhere between 2-8 weeks and are best controlled by removing them from plants and placing them in soapy water.
Other control methods include natural pesticides and encouraging predators like birds into your garden.
 Hussain AG, Wennmann JT, Goergen G, Bryon A, Ros VID. Viruses of the Fall Armyworm Spodoptera frugiperda: A Review with Prospects for Biological Control. Viruses. 2021 Nov 4;13(11):2220. doi: 10.3390/v13112220. PMID: 34835026; PMCID: PMC8625175.