There’s a reason people become much more cautious around yellow jackets toward the end of summer.
A nest that seemed relatively quiet in June can suddenly become a serious problem in September.
Yellow jackets are more active and defensive during late summer and fall, particularly as food becomes harder to find. Rutgers notes that they can sting repeatedly and become extremely defensive when their nests are disturbed.
That makes fall yellow-jacket activity more than just an annoyance. It can become a safety concern for anyone mowing the lawn, trimming bushes, playing outside, or trying to remove a nest.
Why Do Yellow Jackets Get More Aggressive?
The change isn’t because the insects suddenly become angry — their colony is changing.
By late summer, yellow-jacket colonies have reached their peak population. Food sources also become more difficult to find.
That combination can make encounters much more likely. Outdoor activities that disturb a nest can trigger defensive behavior.
Where Do Yellow Jackets Build Nests?
Not all yellow-jacket nests look the same.
Some species build nests underground, including in abandoned rodent burrows. Others build aerial nests in places such as:
- Shrubs
- Trees
- Eaves
- Sheds
- Wall voids
- Attics
- Other protected structures
Rutgers notes that some yellow-jacket species construct paper nests in bushes, sheds, eaves, and other locations.
Why Lawn Mowing Can Be Dangerous
Ground nests are particularly easy to overlook.
A small hole surrounded by grass may not look like a nest entrance. Then a lawn mower passes directly over it.
The vibration can disturb the colony and cause yellow jackets to emerge defensively.
If you suspect a ground nest, avoid mowing directly over the area.
Why Food Attracts Yellow Jackets
Late summer also means outdoor meals, barbecues, ripe fruit, garbage, and sugary drinks. Yellow jackets are attracted to many of these food sources.
That’s why they can become especially noticeable around:
- Garbage cans
- Outdoor kitchens
- Picnic tables
- Fruit trees
- Decks
- Pool areas
Keep food covered and garbage containers closed, but remember that these measures won’t eliminate an established nest.
Should You Remove a Yellow-Jacket Nest Yourself?
This is one pest where DIY treatment deserves extra caution.
Yellow jackets can sting repeatedly, and disturbing a nest can trigger a defensive response.
If you know where a nest is located — especially if it’s inside a wall, underground, near a doorway, or in a heavily used part of your property — professional removal is the safer approach.
What Happens to the Colony in Winter?
The colony does not survive intact through the winter.
Rutgers explains that yellow jackets die off in the fall, with fertile queens surviving to overwinter. Old nests are not reused the following season.
That doesn’t mean you should simply ignore a nest in September or October. A nest can still contain a large number of active yellow jackets while the weather remains favorable.
When to Call Bustabug Pest Control
Call a professional if you’re seeing yellow jackets repeatedly around one location, discovering a ground nest, finding a nest near an entrance, or dealing with activity that makes it difficult to safely use your yard.
Bustabug Pest Control can identify the nest location and determine the appropriate treatment approach.
Yellow Jacket FAQs
Why are yellow jackets worse in September? Colonies are large and yellow jackets become more active and defensive as food becomes less available.
Can yellow jackets sting more than once? Yes. Unlike honey bees, yellow jackets can sting repeatedly.
Are all yellow-jacket nests underground? No. Some species build aerial nests in trees, shrubs, structures, and other protected areas.
Should I mow over a yellow-jacket nest? No. Avoid disturbing a suspected nest and have it professionally assessed.
Will yellow jackets disappear when winter arrives? The colony dies off, but fertile queens survive to overwinter.
Don’t Take Chances With an Active Nest
If yellow jackets have taken over part of your property, don’t risk getting stung trying to eliminate the nest yourself.
Contact Bustabug Pest Control for professional yellow-jacket and stinging-insect control throughout northern New Jersey.