Yellow Jackets in Fall: Why Do They Get More Aggressive?

Yellow jackets in fall can quickly turn a beautiful October afternoon on the patio into an unwelcome game of keep-away. Suddenly, they seem to be interested in your drink, your food, and just about anything else you have outside.

It isn’t your imagination. Yellow jacket behavior changes as summer ends and temperatures begin to cool in St. Louis and St. Charles Counties. Food becomes harder to find, colonies are at or near their largest size, and workers begin searching more aggressively for something to eat.

That can bring them much closer to you and your home.

Why Are Yellow Jackets More Aggressive in the Fall?

During spring and summer, worker yellow jackets spend much of their time finding protein to feed the developing larvae in their colony. In return, the larvae produce a sugary substance that helps feed the adult workers. As fall approaches, the colony’s needs change. Fewer larvae are available to provide that food source, and workers begin looking elsewhere for sugar and carbohydrates. That is why yellow jackets seem particularly interested in your soda, fruit, desserts, trash cans, and food when you’re eating outdoors. Their increased search for food, combined with large late-season colonies, means you may encounter more yellow jackets in September and October than you did earlier in the year.

What Attracts Yellow Jackets to Your Yard in the Fall?

If yellow jackets keep showing up around your home, something nearby may be attracting them.

Common fall attractants include:

• Open trash and recycling containers
• Soda cans and other sweet drinks
• Outdoor meals
• Fallen or overripe fruit
• Pet food
• Sugary spills
• Compost
• Other insects that yellow jackets prey on

Keeping food covered and outdoor areas clean can help reduce their interest in your property, but it won’t eliminate an established nest.

Where Do Yellow Jackets Build Their Nests?

One reason yellow jackets can be difficult to deal with is that their nests aren’t always easy to see. Yellow jackets frequently build nests underground in abandoned animal burrows or other protected cavities. They can also establish nests inside wall voids and other sheltered spaces around a structure. You may notice yellow jackets repeatedly flying in and out of the same small opening. That activity can be one of the first signs that a nest is nearby. Be particularly cautious when mowing, trimming landscaping, cleaning up leaves, or doing other fall yard work. Accidentally disturbing a hidden nest can cause numerous yellow jackets to emerge quickly to defend it.

Do Yellow Jackets Die When the Weather Gets Cold?

Most members of a yellow jacket colony will die as consistently cold weather arrives. Newly produced queens, however, leave the colony and find protected places to overwinter before establishing new colonies the following spring. That doesn’t mean you should automatically ignore a yellow jacket problem and wait for winter. October weather in the St. Louis area can include plenty of warm afternoons, allowing yellow jackets to remain active. A nest located close to an entrance, patio, children’s play area, walkway, or other frequently used space can continue creating problems until cold weather brings the colony’s activity to an end.

How Can You Prevent Yellow Jacket Problems Around Your Home?

Fall prevention starts by making your property less appealing and watching for signs of nest activity. Keep outdoor trash cans tightly closed, clean up spills promptly, remove fallen fruit, avoid leaving pet food outdoors, and cover food and beverages when eating outside. It is also a good time to look around the exterior of your home for openings that could provide access to protected spaces. Check around siding, rooflines, vents, utility penetrations, and other gaps. If you notice repeated yellow jacket activity around one particular location, don’t seal the opening while the nest is active. Yellow jackets trapped inside a wall or structure may look for another way out, potentially sending them into the home.

Should You Remove a Yellow Jacket Nest Yourself?

Yellow jackets defend their colonies and can sting repeatedly. Trying to spray, knock down, dig up, or otherwise disturb an active nest can quickly turn a pest problem into a painful situation. This is especially important when the nest is underground or located inside a structure where you can’t see its size or exact location. Professional pest control can help identify where yellow jackets are nesting and determine the appropriate treatment for the situation.

Fall Pest Control in St. Louis and St. Charles Counties

Yellow jackets are only one of the pests that can remain active as summer turns into fall in Missouri. Ants, mosquitoes, fleas, ticks, and other seasonal pests may continue causing problems around your home throughout the early fall. Preventative pest control can help identify pest activity before it becomes a bigger issue and address the areas around your property that are most likely to attract or harbor pests.

If yellow jackets have taken over your patio, yard, or another area around your home, Vogelsang Pest Management can help.

Contact Vogelsang Pest Management for pest control services in St. Louis and St. Charles Counties and enjoy your fall without sharing it with unwanted guests.