Wasps and other buzzing pests are more prominent in late summer into early fall, but why? The truth is, the behavior has a lot to do with the species, the time of year, and what’s happening inside their nest.
Paper wasps, hornets, mud daubers, and yellowjackets each act differently.
Understanding their behavior makes it easier to manage the risk of stings (and learn when to ignore them if they’re just going about their business).
Honestly, They're Hangry
Most wasp species aren't naturally looking to sting. They sting when defending their nests or when food becomes scarce.
"As the weather cools, wasps’ and yellowjackets’ food resources start to become scarce, with far less to go around than in the spring months," explains Jason Burkhart, Managing Director at Critter Control. "This increased hunger can make them more frustrated, causing them to act aggressively, sometimes even stinging nearby people who are not acting as an overt threat to them."
This seasonal behavior is especially noticeable in late summer and early fall.
"Additionally, in the late summer and early fall, sugar becomes increasingly important for wasp queens, as they prepare for the winter season," adds Burkhart. "This need to gather sugar brings more wasps into areas where they come into contact with humans, which can increase the risk of potential stinging incidents."
That’s why picnics, outdoor trash bins, and backyard gatherings often see more yellowjackets and worker wasps buzzing around at the end of the season.
Nest population is also at its peak population during this time, with thousands of workers defending the colony. This increases the chance of a defensive response if you get too close.
Aggression Levels by Wasp Species
Not all wasps behave the same way. Some are more defensive, others are relatively calm.
- Paper wasps: Usually not aggressive unless their nest is disturbed. Their nests are often attached to shrub branches, under eaves, or tucked against structures.
- Yellowjackets: Among the most aggressive. They build nests in wall voids, underground (we tend to find them the hard way when we're mowing!), and other hidden areas. According to Clemson University in South Carolina, yellowjackets can establish large colonies that survive multiple seasons, with several generations of workers.
- Hornets: Baldfaced hornets (Dolichovespula maculata) are technically yellowjackets, but they act like hornets with aerial nests that can house thousands of workers. They're known for strong defensive responses when their nests are approached. Giant hornets and the yellow-legged hornet aren't native to the U.S., but are raising concern across North America and parts of Southeast Asia, but not because they're after humans—instead, they tend to target honey bee hives.
- Mud daubers: These solitary wasps rarely sting. They build small tube-like nests of mud and don't defend their nests aggressively. Their hunting phase usually involves capturing spiders, not bothering people. Cute little daubers; leave 'em alone!
Aggression comes down to whether you’re dealing with social wasps (like paper wasps, hornets, and yellowjackets) or solitary ones (like mud daubers). Social wasps have more to protect, including their original queen and any generations of workers inside deep nests. That's what makes them more likely to sting.
Nest Traits and Notable Behavior
- Body colors: Many wasp species display bright yellow and black color morphs, a warning signal in nature. Baldfaced hornets, by contrast, are black with white markings. Paper wasps can be reddish or brown. The European paper wasp shows more distinct yellow-and-black striping.
- Nest size: Colonies grow all season. By late summer, nests can house thousands of workers. Peak population = increased defensive response.
- Attack phases: Some hornets follow a sequence—hunting phase, slaughter phase, and occupation phase—but usually only when raiding honey bee hives. They're not following an attack plan to hunt humans... at least, not until humans come between them and their food source.
- Regional variation: Wasps (and many insects) react differently in southern U.S. climates than they do up north. Different climates influence how long nests survive and how aggressive worker wasps become late in the season.
How to Protect Yourself from Stings
"We’re often taught to stand still when stinging insects fly around us, so they won’t perceive us as a threat and leave us alone," notes Burkhart. "Unfortunately, at this time of year, wasps and yellowjackets may end up getting aggressive to the point that they’ll sting you even if you are standing completely still and making yourself as innocuous as possible."
So what’s the best move? He advises you to, "avoid interactions with wasps and yellowjackets altogether," adding "If you spot them in a nearby area, try to avoid approaching that space to the best of your ability. If they do come close to you, don’t stand still and wait for them to leave, but don’t swat at them and dash off either. Just steadily move yourself away from them without making any quick movements that could be misinterpreted by them as an attack."
"Slowly get yourself away from them and do your best not to get near them again."
"If you’re in constant contact with them because they live on or frequent your property, you may want to consider having a trained wildlife removal professional assess and handle the situation for you."
FAQ
Are hornets more dangerous than yellowjackets?
Both can be aggressive, but it depends on the situation. Hornets often build large aerial nests and may respond with multiple stings if disturbed. Yellowjackets, especially when nesting in hidden areas like wall voids or underground, can swarm quickly when threatened.
Do wasps serve any purpose if they’re so aggressive?
Yes! Despite their lousy reputation, wasps are beneficial insects. Many species hunt dead animals and pest insects, helping control populations naturally. Some wasp species also pollinate plants. Their behavior can be a nuisance in late summer; however, they play an important role in our local ecosystems.
