Are There More Annoying Bugs in Chemically Treated Lawns?

A Real-World Observation

Over the past few years, I started noticing something while walking my dog.

When we passed lush, perfect lawns, there were more little annoying gnats swarming around as we walked past.

I’ve always said “chemical” when we got to those perfect yards so my dog could learn that it’s not a lawn we stop at to sniff, pee, or poop. But more and more, those are also the yards where I’m swatting bugs away from my face as we walk down the sidewalk.

When we walk past natural, untreated yards, there are noticeably fewer gnats trying to fly up my nose.

At first, I assumed it was just coincidence.

But after years of noticing the same pattern — treated lawns in our neighborhood seemed to have more nuisance bugs, not fewer — I started digging deeper.

It turns out there’s a very real reason I've noticed this (and no…it’s not that I'm not losing my mind).

Herbicides Don’t Just Kill Weeds — They Disrupt the Entire Lawn Ecosystem

Most lawn herbicides are designed to kill broadleaf plants like clover, chickweed, wild violets, and dandelions.

But those plants are also food sources for beneficial insects, the habitat for predator insects, and part of a diverse soil ecosystem that contribute to microbial diversity. 

Broadleaf herbicides don’t just affect plants — they change the entire ecosystem, both above and below the soil.

When these plants are removed:

• beneficial insects lose habitat
• predator insects decline
• soil biodiversity drops
• plant diversity decreases

This creates the perfect environment for nuisance pests to take over.

Instead of a balanced ecosystem, you get outbreak-style bug populations.

Long-term ecological research supports this pattern. Studies have shown that loss of plant diversity reduces insect diversity and shifts ecosystems from predator-dominated communities to herbivore-dominated ones, which can allow nuisance insects to become more noticeable (Haddad et al., 2009).

In other words — when diversity drops, balance disappears.

In our neighborhood, some homeowners have now called in another company to spray for the nuisance bugs, creating a cycle where biodiversity continues to decline and pest pressure increases.

Pesticides AND herbicide treated lawns! 

Fewer “Good Bugs” = More Nuisance Bugs

In untreated yards, you’ll typically find a mix of:

• beetles
• spiders
• predatory insects
• soil organisms
• pollinators

These creatures naturally keep each other in balance.

But herbicides reduce that diversity creating a monoculture which is less biologically stable. When diversity drops, certain insects — often the irritating ones — multiply quickly.

Research has shown that greater plant diversity reduces herbivore pest abundance and stabilizes ecosystems, while simplified landscapes are more prone to pest outbreaks (Root 1973; Ebeling et al. 2018).

This is why chemically treated lawns can sometimes have:

• more ants
• more mites
• more gnats (A LOT more based on our walks)
• more pests (like fleas)
• more tiny biting insects

Even though the lawn looks “cleaner” every application of broadleaf herbicides resets the yard to low diversity.

Some homeowners try to reintroduce diversity by planting flowers or pollinator strips which can help around the edges of a yard. However, if the lawn is treated regularly with broadleaf herbicides, the overall ecosystem remains limited. 

Even small changes can help improve the balance by allowing some clover to remain, reducing the frequency of treatment - not every month on schedule. Instead, treat just the problem areas - not the entire lawn. 

Add untreated border plantings, and planting native ground covers. 

The more diversity that exists in and around a yard, the more stable the insect population tends to be.

What This Means for Dogs

I know what you are thinking ... this is a dog blog... so what does all of this mean for my dog?

When treated lawns shift insect populations, dogs are often the first to be impacted, resulting in:

• increased itching after walks
• paw licking
• skin irritation
  
• scratching episodes
• increased flea exposure

Many dog parents assume it’s “seasonal allergies,” when in reality it may be environmental exposure to treated lawns and the insects they attract.

The Skin Microbiome Connection

There’s another important piece of this puzzle: your dog’s skin microbiome.

Your dog’s skin is home to a delicate ecosystem of:

• beneficial bacteria
• protective yeast species
• immune-supporting microbes
• natural oils

Environmental exposure plays a major role in shaping this microbiome.

Research has shown that animals exposed to more diverse natural environments develop more stable microbial communities, while reduced biodiversity can disrupt microbial balance (Hanski et al., 2012; Rodrigues Hoffmann et al., 2014).

When dogs walk through heavily treated lawns, they may be exposed to:

• reduced environmental microbial diversity
• chemical residues
• stressed turf ecosystems
• increased nuisance insects

All of which may contribute to itching, inflammation, paw licking, skin imbalance, and ingestion of herbicides which results in bioaccumulation of those toxic chemicals in their bodies (a topic for another day).

Natural Lawns Often Have Fewer Nuisance Bugs

It may seem counterintuitive, but lawns that have clover, avoid herbicides, support biodiversity, and maintain healthy soil have fewer pest outbreaks.

There are still insects — but they’re more balanced. And balanced ecosystems tend to create fewer problems for dogs, both short-term and long-term.

What You Can Do as a Dog Parent

Dogs are incredibly sensitive to environmental changes.

If you dog walks through a chemically treated yard rinse their paws after you get home.

Train them which lawns are safe and which are not.

Don’t forget that it’s not just lawns.  If you take your dog to parks or hiking and camping areas, it’s pretty likely they have been treated too. It’s very hard to find untreated spaces unless it is your own private yard!

Jacey has pretty quickly picked up her cue when I say "Chemicals", she stays on the sidewalk until we get past that yard.

Natural yards don’t just benefit pollinators — they may also mean fewer bug-related irritations for dogs and of course less exposure to toxic chemicals.

If your dog scratches after walking on a perfect lawn they may need a bath to get the chemical residue and possible pests off their body. 

Your dog’s skin — and microbiome — will thank you.

 

References

Haddad NM et al. 2009. Plant species loss decreases arthropod diversity and shifts trophic structure. Ecology Letters.

Root RB. 1973. Organization of a plant-arthropod association in simple and diverse habitats. Ecological Monographs.

Ebeling A et al. 2018. Plant diversity effects on arthropods and ecosystem functioning. Basic and Applied Ecology.

Hanski I et al. 2012. Environmental biodiversity, human microbiota, and allergy. Proceedings of the National Academy of Sciences.

Rodrigues Hoffmann A et al. 2014. The skin microbiome in healthy and allergic dogs. PLoS ONE.